U.S. patent application number 13/816278 was filed with the patent office on 2013-06-06 for liquid composition, recording method, and recorded matter.
The applicant listed for this patent is Hidetoshi Fujii, Hiroshi Gotou, Kiyofumi Nagai. Invention is credited to Hidetoshi Fujii, Hiroshi Gotou, Kiyofumi Nagai.
Application Number | 20130143008 13/816278 |
Document ID | / |
Family ID | 45605280 |
Filed Date | 2013-06-06 |
United States Patent
Application |
20130143008 |
Kind Code |
A1 |
Gotou; Hiroshi ; et
al. |
June 6, 2013 |
LIQUID COMPOSITION, RECORDING METHOD, AND RECORDED MATTER
Abstract
A liquid composition containing: a water-soluble cationic
polymer obtained by polymerizing monomers containing epihalohydrin
and at least one of amine and amide; and water, wherein the liquid
composition is for agglutinating negatively charged particles which
are dispersed in a dispersion liquid.
Inventors: |
Gotou; Hiroshi; (Kanagawa,
JP) ; Fujii; Hidetoshi; (Kanagawa, JP) ;
Nagai; Kiyofumi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gotou; Hiroshi
Fujii; Hidetoshi
Nagai; Kiyofumi |
Kanagawa
Kanagawa
Tokyo |
|
JP
JP
JP |
|
|
Family ID: |
45605280 |
Appl. No.: |
13/816278 |
Filed: |
August 18, 2011 |
PCT Filed: |
August 18, 2011 |
PCT NO: |
PCT/JP2011/069101 |
371 Date: |
February 11, 2013 |
Current U.S.
Class: |
428/195.1 ;
347/20; 524/300; 524/376; 524/608; 524/612 |
Current CPC
Class: |
C08G 73/0293 20130101;
B41M 5/0017 20130101; C08G 73/0213 20130101; C08K 5/19 20130101;
C09D 179/02 20130101; B41J 2/01 20130101; C09D 11/54 20130101; C08L
79/02 20130101; C08G 73/022 20130101; C08G 73/0286 20130101; C08K
5/19 20130101; C09D 11/322 20130101; C08L 79/02 20130101; Y10T
428/24802 20150115; C08K 5/19 20130101; C09D 177/00 20130101 |
Class at
Publication: |
428/195.1 ;
347/20; 524/612; 524/608; 524/300; 524/376 |
International
Class: |
C09D 179/02 20060101
C09D179/02; C09D 177/00 20060101 C09D177/00; B41J 2/01 20060101
B41J002/01 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 19, 2010 |
JP |
2010-184212 |
Claims
1. A liquid composition comprising: a water-soluble cationic
polymer obtained by polymerizing a monomer comprising an
epihalohydrin and at least one selected from the group consisting
of an amine and an amide; and water, wherein the liquid composition
is suitable for agglutinating negatively charged particles
dispersed in a dispersion liquid.
2. The liquid composition according to claim 1, further comprising
an organic acid ammonium salt.
3. The liquid composition according to claim 2, wherein the organic
acid ammonium salt is ammonium lactate.
4. The liquid composition according to claim 1, wherein the
water-soluble cationic polymer is at least one selected from the
group consisting of: a copolymer of formula (1): ##STR00014##
wherein R.sub.1 to R.sub.8 are each independently an alkyl group
comprising 1 to 8 carbon atoms, a hydroxyalkyl group, an alkenyl
group, or a benzyl group, X is a halogen atom, and n is an integer
of 1 or 2; a copolymer comprising a repeating unit of formula (2):
##STR00015## wherein X is a halogen atom, and m is an integer of 1
or more; a copolymer obtained by polymerizing a monomer of formula
(3): ##STR00016## a monomer of formula (4): ##STR00017## and a
monomer of formula (5): ##STR00018## wherein X is a halogen
atom.
5. The liquid composition according to claim 1, wherein the liquid
composition has a surface tension of 30 mN/m or lower.
6. The liquid composition according to claim 1, further comprising:
a fluorine-based surfactant; and a compound of formula (6):
HOR.sub.1R.sub.3C--[CH.sub.2].sub.n--CR.sub.2R.sub.4OH Formula (6),
wherein R.sub.1 and R.sub.2 are each independently an alkyl group
comprising 3 to 6 carbon atoms; R.sub.3 and R.sub.4 are each
independently an alkyl group comprising 1 to 2 carbon atoms; and n
denotes an integer of from 1 to 6.
7. A recording method comprising: adhering a liquid composition
onto a recording medium; and adhering a dispersion liquid
comprising dispersed negatively charged particles comprising a
colorant onto the recording medium, wherein the liquid composition
comprises: a water-soluble cationic polymer obtained by
polymerizing a monomer comprising an epihalohydrin and at least one
selected from the group consisting of an amine and an amide; and
water, wherein the liquid composition is suitable for aggultinating
negatively charged particles dispersed in a dispersion liquid.
8. The recording method according to claim 7, wherein the colorant
is at least one selected from the group consisting of a
self-dispersible pigment, a pigment coated with a resin, and a
pigment dispersed by a dispersant.
9. A recorded matter comprising: an image, wherein the image is
recorded by a recording method, comprising: adhering a liquid
composition onto a recording medium; and adhering a dispersion
liquid comprising dispersed negatively charged particles comprising
a colorant onto the recording medium, wherein the liquid
composition comprises: a water-soluble cationic polymer obtained by
polymerizing a monomer comprising an epihalohydrin and at least one
selected from the group consisting of an amine and an amide; and
water, wherein the liquid composition is suitable for aggultinating
negatively charged particles dispersed in a dispersion liquid.
10. The liquid composition according to claim 1, wherein the
monomer comprises an amine.
11. The liquid composition according to claim 1, wherein the
monomer comprises an amide.
12. The liquid composition according to claim 1, wherein the
monomer comprises an amine and an amide.
13. The liquid composition according to claim 1, wherein the
water-soluble cationic polymer is 1 to 40 mass percent of the
liquid composition.
14. The liquid composition according to claim 1, wherein the
water-soluble cationic polymer is 3 to 30 mass percent of the
liquid composition.
15. The liquid composition according to claim 2, wherein the
organic acid ammonium salt is at least one selected from the group
consisting of ammonium lactate, ammonium acetate, ammonium
propionate, ammonium citrate, ammonium tartrate, ammonium
succinate, diammonium malonate, diammonium hydrogen citrate,
triammonium citrate, and ammonium L-glutamate.
16. The liquid composition according to claim 2, wherein the
organic acid ammonium salt is 1 to 40 mass percent of the liquid
composition.
17. The liquid composition according to claim 2, wherein the
organic acid ammonium salt is 3 to 30 mass percent of the liquid
composition.
18. The liquid composition according to claim 1, further comprising
at least one selected from the group consisting of a surfactant, a
penetrant, and an anti-foaming agent.
19. The liquid composition according to claim 1, further comprising
a surfactant, wherein the surfactant is a fluorine-based
surfactant, a silicone-based surfactant, a nonionic surfactant, an
anionic surfactant, or a betaine-based surfactant.
20. The liquid composition according to claim 19, wherein the
liquid composition comprises a fluorine-based surfactant, wherein
the fluorine-based surfactant is at least one selected from the
group consisting of a perfluoroalkyl sulfonic acid compound, a
perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate
ester compound, a perfluoroalkylethylene oxide adduct, and a
polyoxyalkylene ether polymer compound comprising a perfluoroalkyl
ether group in a side chain.
Description
TECHNICAL FIELD
[0001] The present invention relates to a liquid composition for
agglutinating negatively charged particles, a recording method
using the liquid composition and a recorded matter recorded by the
recording method.
BACKGROUND ART
[0002] In recent years, in accordance with demands for recording a
color image at cheap cost, inkjet recording methods, in which a
plurality of different color inks are applied to a recording medium
having no coating layer, such as plain paper, to thereby record an
image on the recording medium, are used. In this case, since the
inks are provided to the recording medium having no coating layer,
the inks are directly absorbed into paper serving as the base of
the recording medium, and ink bleeding occurs. Thus quality of a
resulting recorded matter easily degrades.
[0003] Then, it can be considered that an image is recorded using
an ink having low permeability to prevent the ink from penetrating
through the recording medium and to thereby prevent bleeding
(referred to as "feathering" hereinbelow) at a boundary portion
between the recording medium and the ink in the recorded matter.
However, in this case, the ink easily retains on a surface of the
recording medium, and accordingly, the drying properties of the
recorded matter degrades. When the drying properties of a recorded
matter degrades, a finger or the like comes into contact with an
ink that has not yet been dried to cause smear on images, and in
the case where a color image is recorded, a different color ink is
attached to the ink that has not yet been dried, and the color inks
are mixed, causing bleeding (referred to as "color bleeding"
hereinbelow) at a boundary portion between these inks. Meanwhile,
when an ink having high permeability is used to prevent the
occurrence of color bleeding, there is a problem that the
above-noted feathering occurs and the quality of a resulting
recorded matter degrades.
[0004] To simultaneously solve these problems, there has been
proposed a recording method using an ink and a liquid composition
for fixing the ink on a recording medium. For example, there has
been proposed an inkjet recording method in which a reaction liquid
containing polyallylamine and an ink composition which contains a
colorant and a resin emulsion are made adhere to a surface of a
recording medium to thereby perform recording (see PTL 1).
According to this proposal, print bleeding and printing
nonuniformity can be reduced on a recording medium, and moreover
color bleeding can be effectively prevented thereon.
CITATION LIST
Patent Literature
[0005] PTL 1 Japanese Patent (JP-B) No. 3206797
SUMMARY OF INVENTION
Technical Problem
[0006] However, the recording method of this proposal has a problem
in terms of fixability of the ink composition on a recording
medium. In other words, when the ink composition is made to adhere
to a surface of the recording medium on which the liquid
composition has been made to adhere, the pigment and the resin
emulsion contained in the ink come into contact with polyallylamine
which is positively charged, and rapidly agglutinate, and thus
aggregates containing a small amount of vehicle (which means a
liquid component in the reaction liquid or the ink composition) are
accumulated on the outermost surface of the recording medium. The
accumulated layer is weak in resistance to abrasion (referred to as
"abrasion resistance" hereinbelow), and therefore, such a problem
occurs that user's hand may be smeared with the ink when being in
contact with a recorded matter, or the rear surface of a recorded
matter may be smeared with the ink when being in contact with
another recorded matter. In addition, after an image recorded by
this inkjet recording method was analyzed, it was found that the
diameter of each dot recorded was small. It is considered that this
may be caused because the reaction liquid has a strong effect to
cause the ink to agglutinate. When the diameter of each dot is
excessively small, there is a problem that white-out (which means
portions where no ink adheres in a recorded solid image) occur.
[0007] The present invention solves the conventional problems and
achieves the following object. That is, the present invention aims
to provide a liquid composition, which can form an image with high
density on a recording medium, can effectively prevent occurrence
of strikethrough, feathering, and color bleeding, can decrease
occurrence of white-out, gives excellent abrasion resistance to
resulting images, and has excellent drying properties and
coatability, provide a recording method using the liquid
composition, and provide a recorded matter recorded by the
recording method.
Solution to Problem
[0008] Means for solving the problems are as follows.
<1> A liquid composition containing: a water-soluble cationic
polymer obtained by polymerizing monomers containing epihalohydrin
and at least one of amine and amide; and water, wherein the liquid
composition is for agglutinating negatively charged particles which
are dispersed in a dispersion liquid. <7> A recording method
including making the liquid composition according to <1>
adhere onto a recording medium; and making a dispersion liquid, in
which negatively charged and colorant-containing particles which
are dispersed, adhere onto the recording medium onto which the
liquid composition has been made to adhere. <9> A recorded
matter containing: an image, wherein the image is recorded by the
recording method according to <7>.
Advantageous Effects of Invention
[0009] When a dispersion liquid, in which negatively charged
particles are dispersed, is applied to a recording medium to which
a liquid composition of the present invention has been made to
adhere, a dispersion medium contained in the dispersion liquid is
diffused by the action of a water-soluble cationic polymer
contained in the liquid composition, and at the same time, the
particles contained therein agglutinate. With the occurrence of
diffusion of the dispersion medium and agglutination of the
particles, the colorant is fixed at a shallow portion inside the
recording medium, to thereby obtain a recorded matter having
excellent fixability.
[0010] The present invention solves the conventional problems and
achieves the following object. That is, the present invention aims
to provide a liquid composition, which can form an image with high
density on a recording medium, can effectively prevent occurrence
of strikethrough, feathering, and color bleeding, can decrease
occurrence of white-out, gives excellent abrasion resistance to
resulting images, and has excellent drying properties and
coatability, provide a recording method using the liquid
composition, and provide a recorded matter recorded by the
recording method.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIGS. 1A to 1C are schematic cross-sectional views each
illustrating a state of a recorded portion in a recorded matter of
the present embodiment.
[0012] FIG. 2 is a cross-sectional side view illustrating one
example of an apparatus for use in a recording method of the
present embodiment.
[0013] FIG. 3 is a cross-sectional side view illustrating another
example of the apparatus for use in a recording method of the
present embodiment.
DESCRIPTION OF EMBODIMENTS
(Liquid Composition)
[0014] A liquid composition of the present invention is a liquid
composition for agglutinating negatively charged particles, which
are dispersed in a dispersion liquid, the liquid composition
containing water, and a water-soluble cationic polymer obtained by
polymerizing a monomer containing epihalohydrin and at least one of
amine and amide, and if necessary further containing other
components such as organic acid ammonium salt.
[0015] Hereinafter, with reference to preferred embodiments, the
liquid composition of the present embodiment will be further
described in detail. An expected mechanism of fixation of a
dispersion liquid using the liquid composition of the present
invention is described using FIGS. 1A to 1C. Here, the dispersion
liquid is an ink, in which negatively charged and
colorant-containing particles which are dispersed. FIGS. 1A to 1C
are schematic cross-sectional views for each describing a state of
a recorded portion in a recorded matter of the present
embodiment.
[0016] When the liquid composition of the present embodiment is
applied to a recording medium 101 made of a paper body, a liquid
composition-attached portion 102 is formed on the recording medium
101 (see FIG. 1A). To the liquid composition-attached portion 102,
an ink, in which negatively charged and colorant-containing
particles 103 are dispersed in a dispersion medium 104 (hereinafter
referred to as a "vehicle"), is applied. Examples of the negatively
charged and colorant-containing particles 103 include colorant
particles having a negative charge, and particles containing a
colorant and a compound having a negative charge.
[0017] In the case where an ink is applied onto the liquid
composition-attached portion 102, the ink is in contact with the
liquid composition contained in liquid composition-attached portion
102 (see FIG. 1B). In this case, a water-soluble cationic polymer
contained in the liquid composition acts so that the concentration
of hydrogen ions (pH) and metal ions do not greatly vary (buffering
action). For this reason, the followings can be prevented: the
colorant contained in the ink sharply agglutinates due to an acid
and/or base reaction and/or a large amount of the colorant
precipitates on the recording medium. As a result, the ink spread
on the surface of the recording medium (the direction of arrow A in
FIG. 1B), the area of dots recorded is increased, to thereby
increase the density of an image (which includes characters,
symbols etc.).
[0018] Subsequently, when an ink penetrates into the liquid
composition-attached portion 102 of the recording medium 101 (the
direction of arrow B in FIG. 1B), a colorant contained in the ink
agglutinate by the action of the water-soluble cationic polymer,
and is fixed on the recording medium (see FIG. 1C). It is inferred
that the colorant is fixed at a shallow position inside the
recording medium in this way, thereby improving the fixability, and
reducing the occurrence of feathering and color bleeding.
[0019] It is desired that the liquid composition of the present
embodiment be quickly absorbed into a recording medium after being
applied to the recording medium. In the present embodiment, "dry",
"drying" or "dried", etc. means a state that the liquid composition
is absorbed into the recording medium. In order to quickly dry the
liquid composition, the surface tension of the liquid composition
is preferably 30 mN/m or lower. Note that it is enough for the
liquid composition to be dried after being applied to the recording
medium, and there is no need that a liquid such as water contained
in the vehicle be vaporized to be unable to keep the liquid state,
and the dried liquid composition allows to fix the ink and to
improve the quality of an image to be recorded. In the present
embodiment, "solidification", "solidify" or "solidified", etc.
means a state that a liquid such as water contained in the vehicle
is vaporized to be unable to keep the liquid state. Next,
components, for example, the water-soluble cationic polymer,
contained the liquid composition of the present embodiment will be
described hereinbelow.
<Water-Soluble Cationic Polymer>
[0020] As the water-soluble cationic polymer used in the liquid
composition of the present embodiment, a water-soluble cationic
polymer obtained by polymerizing a monomer containing epihalohydrin
and at least one of amine and amide is used. The water-soluble
cationic polymer obtained by polymerizing such monomer contains a
hydroxyl group and ammonium cation, etc. in a main chain. It is
inferred that when the water-soluble cationic polymer is in contact
with an ink, the water-soluble cationic polymer has a function of
enhancing the buffering action and the action of agglutinating a
colorant as halogen anions contained in the water-soluble cationic
polymer is isolated into an aqueous solution of the water-soluble
cationic polymer.
[0021] The water-soluble cationic polymer is not particularly
limited and may be suitably selected in accordance with the
intended use. Suitable examples thereof include a
polyamine-epihalohydrin copolymer, a polyamide-epihalohydrin
copolymer, a polyamidepolyamine-epihalohydrin copolymer, an
amine-epihalohydrin copolymer. Among these, at least one selected
from a copolymer represented by Formula (1), a copolymer having a
repeating unit represented by Formula (2), and a copolymer obtained
by polymerizing an amine monomer, a monomer represented by Formula
(4) and a monomer represented by Formula (5) is more preferable.
Examples of the amine monomer include diethylenetriamine,
triethylenetetramine, and tetraethylenepentamine, and
iminobispropylamine. The monomer represented by Formula (3) is
preferable, because it is industrially produced and easily
obtainable. Note that as the above-described water-soluble cationic
polymer, other than the above exemplary compounds, a quaternary
ammonium salt type cationic polymer, or in some cases a
water-dispersible cationic polymer may be used.
##STR00001##
[0022] in Formula (1), R.sub.1 to R.sub.8 may be identical to or
different from each other, and each denote at least one of an alkyl
group having 1 to 8 carbon atoms, a hydroxyalkyl group, an alkenyl
group, and a benzyl group, X denotes a halogen atom (for example,
F, Cl, Br, I), n denotes an integer of 1 or 2.
##STR00002##
[0023] in Formula (2), X denotes a halogen atom (for example, F,
Cl, Br, I), and m denotes an integer of 1 or more. Both-terminal of
the copolymer represented by Formula (2) may be a monomer
constituting a repeating unit, a known initiator, or the like.
##STR00003##
[0024] in Formula (5), X denotes a halogen atom (for example, F,
Cl, Br, and I).
[0025] The water-soluble cationic polymer is obtained by known
methods such as a method for polymerizing a monomer containing
epihalohydrin and at least one of amine and amide, a method for
graft polymerization of a monomer containing epihalohydrin with
polyamide which is obtained by polymerizing a monomer containing
amine and carboxylic acid.
[0026] The weight average molecular weight of the water-soluble
cationic polymer differs depending on types of copolymers. In the
case of the polyamine-epihalohydrin copolymer, the weight average
molecular weight of the water-soluble cationic polymer is
preferably 500 to 100,000. In the case of the
polyamide-epihalohydrin copolymer or the
polyamidepolyamine-epihalohydrin copolymer, the weight average
molecular weight of the water-soluble cationic polymer is
preferably 5,000,000 or less. In the case of the
polyamine-epihalohydrin copolymer, the weight average molecular
weight of the water-soluble cationic polymer is preferably 700 to
50,000. When the weight average molecular weight is more than the
maximum value of each copolymer, an aqueous solution may not be
formed. When the weight average molecular weight is less than the
minimum value of each copolymer, effect of treatment with the
liquid composition may be decreased.
[0027] The addition amount of the water-soluble cationic polymer is
not particularly limited and may be suitably selected in accordance
with the intended use. The addition amount of the water-soluble
cationic polymer is preferably 1% by mass to 40% by mass, and more
preferably 3% by mass to 30% by mass, relative to the total amount
of the liquid composition of the present embodiment. When the
addition amount is more than 40% by mass, the effect of improving
the quality of an image in commensurate with the increased addition
amount may not change, and the viscosity of the liquid composition
may excessively increase. When the addition amount is less than 1%
by mass, there is a possibility that the effect of improving the
quality of an image is reduced.
<Organic Acid Ammonium Salt>
[0028] The liquid composition of the present embodiment preferably
contains an organic acid ammonium salt, in order to improve quality
of an image to be formed.
[0029] The organic acid ammonium is not particularly limited and
may be suitably selected in accordance with the intended use. From
the standpoint of solubility to water, ammonium lactate, ammonium
acetate, ammonium propionate, ammonium citrate, ammonium tartrate,
ammonium succinate (diammonium succinate), diammonium malonate,
diammonium hydrogen citrate, triammonium citrate, and ammonium
L-glutamate are preferable, with more preference given to ammonium
lactate.
[0030] The addition amount of the organic acid ammonium salt is not
particularly limited and may be suitably selected in accordance
with the intended use. It is preferably 1% by mass to 40% by mass,
more preferably 3% by mass to 30% by mass, relative to the liquid
composition. When the addition amount is more than 40% by mass, the
quality of an image in commensurate with the increased addition
amount may not be improved, and the viscosity of the liquid
composition may excessively increase. When the addition amount is
less than 1% by mass, there is a possibility that the effect of
improving the quality of an image is reduced.
<Water-Soluble Organic Solvent>
[0031] The water-soluble organic solvent for use in the liquid
composition of the present embodiment is used for retaining water
contained in the liquid composition. With use of the water-soluble
organic solvent, an increase in viscosity of the liquid composition
can be suppressed and the discharge stability can be maintained,
even when water or the like in the liquid composition vaporizes in
a nozzle for providing thereof or in a coater. For this reason, as
the water-soluble organic solvent, it is preferable to use a
water-soluble organic solvent having high-equilibrium water
content. Here, the equilibrium water content means a water content
when a mixture of a water-soluble organic solvent and water is
released in the air at a constant temperature and a constant
humidity, the evaporation of water in the solution and the
absorption of water in the air into the ink is in an equilibrium
condition. In the present embodiment, the water content equilibrium
is determined as follows: a petri dish in which the water-soluble
organic solvent is weighed in an amount of 1 g is stored for a
period until the mass thereof does not change, in a desiccator in
which the temperature and humidity are maintained at 23.degree.
C..+-.1.degree. C. and 80%.+-.3% using a saturated potassium
chloride aqueous liquid, and the water content equilibrium is
determined by the following equation.
Equilibrium Water Content (% by mass)=(Amount of water absorbed
into water-soluble organic solvent)/(Amount of water-soluble
organic solvent+Amount of water absorbed into water-soluble organic
solvent).times.100
[0032] The water-soluble organic solvent is not particularly
limited and may be suitably selected in accordance with the
intended use. Examples thereof include polyhydric alcohols,
polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers,
nitrogen-containing heterocyclic compounds, amides, amines,
sulfur-containing compounds, propylene carbonate, and ethylene
carbonate. Among these, a water-soluble organic solvent having an
equilibrium water content of 30% by mass or more under the
environment of 23.degree. C. and 80% RH is preferable, and a
water-soluble organic solvent having such an equilibrium water
content of 40% by mass or more under the environment of 23.degree.
C. and 80% RH is more preferable (which is referred to as
"water-soluble organic solvent A", hereinbelow).
[0033] As the water-soluble organic solvent A, polyhydric alcohols
are preferably used. Specific examples thereof include
1,2,3-butanetriol (boiling point (hereinafter abbreviated as bp)
175.degree. C./atmospheric pressure at which the boiling point is
measured (described only when the atmospheric pressure is not 1
hPa) 33 hPa; equilibrium water content: 38% by mass),
1,2,4-butanetriol (bp: 190.degree. C. to 191.degree. C./24 hPa; 41%
by mass), glycerin (bp: 290.degree. C.; 49% by mass), diglycerin
(bp: 270.degree. C./20 hPa; 38% by mass), triethylene glycol (bp:
285.degree. C.; 39% by mass), tetraethylene glycol (bp: 324.degree.
C. to 330.degree. C.; 37% by mass), diethylene glycol (bp:
245.degree. C.; 43% by mass), 1,3-butanediol (bp: 203.degree. C. to
204.degree. C.; 35% by mass). Among these, glycerin, and
1,3-butanediol are particularly preferably used because they show a
low viscosity when they contain water and can be stably maintained
without causing the colorant to agglutinate. When the water-soluble
organic solvent A is used in an amount of 50% by mass relative to
the total amount of water-soluble organic solvents, it is
preferable in that the discharge stability of the liquid
composition can be improved, and fixing of the liquid composition
in a recording apparatus can be prevented.
[0034] In the liquid composition of the present embodiment, a
water-soluble organic solvent having an equilibrium water content
of less than 30% by mass at 23.degree. C. and 80% RH (which is
referred to as "water-soluble organic solvent B" hereinbelow) may
be used instead of the water-soluble organic solvent A or in
addition to the water-soluble organic solvent A. Examples of the
water-soluble organic solvent B include polyhydric alcohols,
polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers,
nitrogen-containing heterocyclic compounds, amides, amines,
sulfur-containing compounds, propylene carbonate, ethylene
carbonate, and other water-soluble organic solvents.
[0035] Specific examples of the polyhydric alcohols for the
water-soluble organic solvent B include dipropylene glycol (bp:
232.degree. C.), 1,5-pentanediol (bp: 242.degree. C.),
3-methyl-1,3-butanediol (bp: 203.degree. C.), propylene glycol (bp:
187.degree. C.), 2-methyl-2,4-pentanediol (bp: 197.degree. C.),
ethylene glycol (bp: 196.degree. C. to 198.degree. C.),
tripropylene glycol (bp: 267.degree. C.), hexylene glycol (bp:
197.degree. C.), polyethylene glycol (viscosity-adjusted liquid to
solid), polypropylene glycol (bp: 187.degree. C.), 1,6-hexanediol
(bp: 253.degree. C. to 260.degree. C.), 1,2,6-hexanetriol (bp:
178.degree. C.), trimethylol ethane (solid, melting point
(hereinafter abbreviated as mp): 199.degree. C. to 201.degree. C.),
and trimethylol propane (solid, mp: 61.degree. C.).
[0036] Examples of the polyhydric alcohol alkyl ethers for the
water-soluble organic solvent B include ethylene glycol monoethyl
ether (bp: 135.degree. C.), ethylene glycol monobutyl ether (bp:
171.degree. C.), diethylene glycol monomethyl ether (bp:
194.degree. C.), diethylene glycol monoethyl ether (bp: 197.degree.
C.), diethylene glycol monobutyl ether (bp: 231.degree. C.),
ethylene glycol mono-2-ethylhexyl ether (bp: 229.degree. C.), and
propylene glycol monoethyl ether (bp: 132.degree. C.).
[0037] Examples of the polyhydric alcohol aryl ethers for the
water-soluble organic solvent B include ethylene glycol monophenyl
ether (bp: 237.degree. C.), and ethylene glycol monobenzyl
ether.
[0038] Examples of the nitrogen-containing heterocyclic compound
for the water-soluble organic solvent B include 2-pyrrolidone (bp:
250.degree. C., mp: 25.5.degree. C., 47% by mass to 48% by mass),
N-methyl-2-pyrrolidone (bp: 202.degree. C.),
1,3-dimethyl-2-imidazolidinone (bp: 226.degree. C.),
.epsilon.-caprolactam (bp: 270.degree. C.), and
.gamma.-butylolactone (bp: 204.degree. C. to 205.degree. C.).
[0039] Examples of the amides for the water-soluble organic solvent
B include formamide (bp: 210.degree. C.), N-methylformamide (bp:
199.degree. C. to 201.degree. C.), N,N-dimethylformamide (bp:
153.degree. C.), and N,N-diethylformamide (bp: 176.degree. C. to
177.degree. C.).
[0040] Examples of the amines for the water-soluble organic solvent
B include monoethanolamine (bp: 170.degree. C.), diethanolamine
(bp: 268.degree. C.), triethanolamine (bp: 360.degree. C.),
N,N-dimethylmonoethanolamine (bp: 139.degree. C.),
N-methyldiethanolamine (bp: 243.degree. C.), N-methylethanolamine
(bp: 159.degree. C.), N-phenylethanolamine (bp: 282.degree. C. to
287.degree. C.), and 3-aminopropyldiethylamine (bp: 169.degree.
C.).
[0041] Examples of the sulfur-containing compounds for the
water-soluble organic solvent B include dimethylsulfoxide (bp:
139.degree. C.), sulfolane (bp: 285.degree. C.), and thiodiglycol
(bp: 282.degree. C.).
[0042] As for the other solid water-soluble organic solvents for
the water-soluble organic solvent B, sugar and the like are
preferable.
[0043] Examples of the sugar include monosaccharides,
disaccharides, oligosaccharides (including trisaccharides, and
tetrasaccharides), and polysaccharides. Specific examples of the
sugar include glucose, mannose, fructose, ribose, xylose,
arabinose, galactose, maltose, cellobiose, lactose, sucrose,
trehalose, and malttriose. Here, the term "polysaccharides" means a
saccharide in a broad sense, and is used herein it encompasses
substances which are broadly present in nature such as
.alpha.-cyclodextrin, and cellulose. In addition, as derivatives of
these sugars, there may be exemplified reducing sugars of the
above-mentioned sugars (e.g., sugar alcohol represented by Formula:
HOCH.sub.2(CHOH).sub.nCH.sub.2OH (where n denotes an integer of 2
to 5), acid sugar (e.g., aldonic acid, and uronic acid), amino
acid, and thio acid. Among these, sugar alcohol is preferable.
Specific examples of the sugar alcohol include maltitol, and
sorbitol.
[0044] The amount of the water-soluble organic solvent contained in
the liquid composition is not particularly limited. It is usually
10% by mass to 80% by mass, and more preferably 15% by mass to 60%
by mass. When the amount of the water-soluble organic solvent is
more than 80% by mass, there is a probability that the drying
properties of a recording medium to which the liquid composition
has been made to adhere degrades, depending on the types of the
water-soluble organic solvents. When the amount of the
water-soluble organic solvent is less than 10% by mass, water
contained in the liquid composition easily vaporizes, and the
viscosity of the liquid composition is increased as vaporization
proceeds, which may lead to a failure in the coating step.
<Other Components>
[0045] Next, other components to be added to the liquid composition
of the present embodiment will be described. The liquid composition
of the present embodiment contains may further contain a
surfactant, a penetrant, an anti-foaming agent, and the like, in
addition to the above-described components.
<<Surfactant>>
[0046] The liquid composition of the present embodiment may contain
a surfactant for improving the wetting properties of a recording
medium; the image density and color saturation of a recorded
matter, preventing white-out (this means that blank portions remain
in image portions of a recorded matter), and for causing a vehicle
in an ink quickly penetrate into a recording medium to thereby
improve the fixability. In this case, the amount of the surfactant
is preferably 0.001% by mass to 5% by mass, and more preferably
0.05% by mass to 2% by mass, relative to the total amount of the
liquid composition. When the amount of the surfactant is less than
0.001% by mass, the effect of adding the surfactant may be reduced,
and when it is more than 5% by mass, it may make no difference in
effect obtained by increasing the addition amount thereof.
[0047] The surfactant is not particularly limited and may be
suitably selected in accordance with the intended use. Examples of
the surfactant include fluorine-based surfactants, silicone-based
surfactants, nonionic surfactants, anionic surfactants, and
betaine-based surfactants. Fluorine-based surfactants are
particularly preferred. These surfactants may be used alone or in
combination.
[0048] In addition, as the fluorine-based surfactant, a
fluorine-based surfactant having 2 to 16 carbon atoms substituted
with fluorine is preferable, and a fluorine-based surfactant having
4 to 16 such carbon atoms is more preferable. When the number of
carbon atoms substituted with fluorine is less than 2, the effect
of using the fluorine-based surfactant may not be obtained, and
when it is more than 16, it may cause a problem with storage
stability.
[0049] The fluorine-based surfactant is not particularly limited
and may be suitably selected in accordance with the intended use.
Examples thereof include a perfluoroalkyl sulfonic acid compound, a
perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate
ester compound, a perfluoroalkylethylene oxide adduct, and a
polyoxyalkylene ether polymer compound having a perfluoroalkyl
ether group in the side chain. Among these, a fluorine-based
surfactant having a perfluoroalkyl group is preferable. A
fluorine-based surfactant represented by the following Formulae
(F-1) to (F-4) is particularly preferable.
C.sub.nF.sub.2n+1--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.a--Y-
' Formula (F-1)
[0050] in Formula (F-1), n denotes an integer of 2 to 6; "a"
denotes an integer of 15 to 50, and Y' denotes --C.sub.bH.sub.2b+1
(b denotes an integer of 11 to 19) or
--CH.sub.2CH(OH)CH.sub.2--C.sub.dF.sub.2d+1 (d denotes an integer
of 2 to 6).
CF.sub.3CF.sub.2(CF.sub.2CF.sub.2).sub.j--CH.sub.2CH.sub.2O--(CH.sub.2CH-
.sub.2O).sub.kH Formula (F-2)
[0051] in Formula (F-2), j denotes an integer of 0 to 10, and k
denotes an integer of 0 to 40.
##STR00004##
[0052] in Formula (F-3), Rf denotes a perfluoroalkyl group; m
denotes an integer of 6 to 25; and n and p each denote an integer
of 1 to 4.
##STR00005##
[0053] in Formula (F-4), Rf denotes a perfluoroalkyl group; X
denotes a quaternary ammonium group; an alkali metal such as sodium
and potassium; triethylamine, or triethanolamine; Y denotes
--COO.sup.-, --SO.sub.3.sup.-, --SO.sub.4.sup.-, or
--PO.sub.4.sup.-; and q denotes an integer of 1 to 6.
[0054] Preferred examples of a compound represented by Formula
(F-1) are compounds each represented by any one of the following
structural formulae a) to u), for their high-ability to reduce a
surface tension and their high permeability. Among these, compounds
represented by e), f), s), t) or u) are preferable because of their
excellence in compatibility with an anti-foaming agent represented
by the formula (6) below.
a)
C.sub.4F.sub.9--COO--(CH.sub.2CH.sub.2O).sub.23--C.sub.12H.sub.25
b)
C.sub.4F.sub.9--SO.sub.2N(CH.sub.3)--(CH.sub.2CH.sub.2O).sub.21--C.su-
b.12H.sub.25
c)
C.sub.4F.sub.9--CH.sub.2CH.sub.2O--CH.sub.2CH.sub.2O).sub.25--C.sub.1-
2H.sub.25
d)
H(CF.sub.2).sub.4--CH.sub.2OCH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.-
2O).sub.21--C.sub.14H.sub.29
e)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.21---
C.sub.12H.sub.25
f)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.25---
C.sub.12H.sub.25
g)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.30---
C.sub.12H.sub.25
h)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.20---
C.sub.14H.sub.29
i)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.30---
C.sub.14H.sub.29
j)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.23---
C.sub.16H.sub.33
k)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.20---
C.sub.16H.sub.33
l)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.25---
C.sub.16H.sub.33
m)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.30---
C.sub.16H.sub.33
n)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.40---
C.sub.16H.sub.33
o)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.20---
C.sub.18H.sub.37
q)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.30---
C.sub.18H.sub.37
r)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.40---
C.sub.18H.sub.37
s)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.23---
CH.sub.2CH(OH)CH.sub.2--C.sub.4F.sub.9
t)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.35CH-
.sub.2CH(OH)CH.sub.2--C.sub.4F.sub.9
u)
C.sub.4F.sub.9--CH.sub.2CH(OH)CH.sub.2O--(CH.sub.2CH.sub.2O).sub.45---
CH.sub.2CH(OH)CH.sub.2--C.sub.4F.sub.9
[0055] In a compound represented by Formula (F-1) above, a
(Hydrophile-Lipophile Balance) value determined by Griffin's method
is preferably 10 to 16 for the reason of the solubility in an
aqueous ink. In addition, in the compound represented by Formula
(F-1), a ratio MWEO/MWF of a molecular weight (MWEO) of a
polyoxyethylene group [(CH.sub.2CH.sub.2O).sub.a portion] to a
molecular weight (MWF) of a fluoroalkyl group (C.sub.nF.sub.2n+1
portion and C.sub.mF.sub.2m+1 portion) is preferably 2.2 to 10 for
the reason of balance between the functionality as a surfactant and
the solubility in water.
[0056] In a compound represented by Formula (F-2) above, j is
preferably an integer of 0 to 10, and k is preferably an integer of
0 to 40, in order to improve ability to reduce a surface tension
and improve high permeability. As for the compound represented by
(F-2) above, a commercially available fluorine-based surfactant can
be used. Examples of such commercially available surfactant include
SURFRON S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145
(produced by Asahi Glass Co.); FLUORAD FC-93, FC-95, FC-98, FC-129,
FC-135, FC-170C, FC-430, FC-431, and FC-4430 (produced by Sumitomo
3M Ltd.); MEGAFACE F-470, F-1405, and F-474 (produced by Dainippon
Ink and Chemicals, Inc.); ZONYL FS-300, FSN, FSN-100, and FSO
(produced by DuPont); EFTOP EF-351, EF-352, EF-801, and EF-802
(produced by Mitsubishi Materials Electronic Chemicals Co., Ltd.).
Among these products, ZONYL FS-300, FSN, FSN-100, and FSO (produced
by DuPont) are particularly preferable for their high reliability
and excellence in color saturation. These commercially products are
each a mixture of compounds having several kinds of molecular
weights, and in most case, j and k in Formula (F-2) have a
distribution, however, in the present embodiment, these
commercially available products can be used without any
problems.
[0057] In a compound represented by Formula (F-3) above, as Rf, a
perfluoroalkyl group is preferably used in order to improve ability
to reduce a surface tension and improve high permeability. As for
the perfluoroalkyl group, the one having 1 to 10 carbon atoms is
preferable, and the one having 1 to 3 carbon atoms is more
preferable. Examples of such a perfluoroalkyl group include those
represented by --C.sub.nF.sub.2n-1 (where n is an integer of 1 to
10), for example, --CF.sub.3, --CF.sub.2CF.sub.3, --C.sub.3F.sub.7,
and --C.sub.4F.sub.9. Among these perfluoroalkyl groups,
--CF.sub.3, and --CF.sub.2CF.sub.3 are particularly preferable. In
a compound represented by Formula (F-3), m, n, and p each denote an
integer; n is preferably an integer of 1 to 4; m is preferably an
integer of 6 to 25; and p is preferably an integer of 1 to 4.
[0058] As Rf in a compound represented by Formula (F-4), a similar
perfluoroalkyl group to that described in Formula (F-3) is
preferably used. For example, --CF.sub.3, --CF.sub.2CF.sub.3,
--C.sub.3F.sub.7, --C.sub.4F.sub.9 and the like are preferably
used. In a compound represented by Formula (F-4), X denotes a
cation group. Examples thereof include a quaternary ammonium group;
alkali metals such as sodium, and potassium; triethylamine, and
triethanolamine. Among these, quaternary ammonium group is
particularly preferable. In the compound represented by Formula
(F-4), Y denotes an anion group. Examples thereof include
--COO.sup.-, --SO.sub.3.sup.-, --SO.sub.4.sup.-, and
--PO.sub.4.sup.-.
[0059] In Formula (F-4), q denotes an integer, and is preferably an
integer of 1 to 6.
[0060] As the at least one fluorine-based surfactant selected from
the compounds represented by one of Formulae (F-3) and (F-4), a
compound selected from compounds represented by one of Formulae
(F-3-1) and (F-4-1) is preferable from the standpoint of
safety.
##STR00006##
[0061] in Formula (F-3-1), Rf denotes --CF.sub.3, or
--CF.sub.2CF.sub.3; n denotes an integer of 1 to 4; m denotes an
integer of 6 to 25; and p denotes an integer of 1 to 4.
##STR00007##
[0062] in Formula (F-4-1), Rf denotes --CF.sub.3, or
--CF.sub.2CF.sub.3; and q denotes an integer of 1 to 6.
[0063] The amount of the fluorine-based surfactant contained in the
liquid composition of the present embodiment is preferably 0.01% by
mass to 10% by mass, and more preferably 0.03% by mass to 5% by
mass. When the amount of the fluorine-based surfactant is less than
0.01% by mass, an visually observable effect of improvement in
color saturation may not be obtained, and an effect of causing a
vehicle in the ink quickly penetrate into a recording medium to
improve the fixability may not be obtained. When the amount of the
fluorine-based surfactant is more than 10% by mass, the effect may
not change even when the addition amount thereof is increased, and
the fluorine-based surfactant may not be dissolved into a
pretreatment liquid, and thus the physical properties of the
resulting liquid may be unstable.
[0064] In the liquid composition of the present embodiment, the
fluorine-based surfactants selected from Formulae (F-1) to (F-4)
may be used alone or in combination. Further, the fluorine-based
surfactant may be used in combination with another fluorine-based
surfactant, a nonionic surfactant, an anionic surfactant, an
amphoteric surfactant, an acetylene glycol-based surfactant, or the
like.
<<Penetrant>>
[0065] The liquid composition of the present embodiment preferably
contains as the penetrant at least one of non-wettable polyol
compounds having 8 to 11 carbon atoms, and glycol ether compounds.
Among these, preferred are those having solubility from 0.2% by
mass to 5.0% by mass in water of 25.degree. C., with
2-ethyl-1,3-hexanediol (solubility: 4.2% (25.degree. C.)), and
2,2,4-trimethyl-1,3-pentanediol (solubility: 2.0% (25.degree. C.))
being particularly preferable.
[0066] Examples of the non-wettable polyol compound include fatty
acid diols such as 2-ethyl-2-methyl-1,3-propanediol,
3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1,3-propanediol,
2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol,
2,5-dimethyl-2,5-hexanediol, and 5-hexene-1,2-diol.
[0067] Other penetrants usable in combination are not particularly
limited, as long as it can be dissolved into the liquid composition
to thereby adjust physical properties of the liquid composition to
desired physical properties, and may be suitably selected in
accordance with the intended use. Examples thereof include alkyl
ethers and aryl ethers of polyhydric alcohols such as diethylene
glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene
glycol monoallyl ether, diethylene glycol monophenyl ether,
diethylene glycol monobutyl ether, propylene glycol monobutyl
ether, tetraethylene glycol chlorophenyl ether; and lower alcohols
such as ethanol.
[0068] The amount of the penetrant contained in the liquid
composition is preferably 0.1% by mass to 5.0% by mass. When the
amount of the penetrant is less than 0.1% by mass, the effect of
causing the liquid composition to penetrate into a recording medium
may wear off. When the amount is more than 5.0% by mass, the
penetrant segregates from the solvent due to the low solubility of
the penetrant thereto, and thus the effect of improving the
permeability of the liquid composition may be saturated.
<<Anti-Foaming Agent>>
[0069] The liquid composition of the present embodiment may contain
an anti-foaming agent for the purpose of suppressing foaming (which
means that a liquid is formed into a thin film to enfold air).
Generally, a liquid having high surface tension, like water, hardly
foams because a force of reducing the surface area thereof as much
as possible works. Whereas a liquid having low surface tension and
high viscosity easily foams, foams generated are retained and
hardly removed. When the liquid composition of the present
embodiment contains the above-mentioned water-soluble cationic
polymer, water-soluble organic solvent, surfactant and the like,
the surface tension thereof decreases and the viscosity thereof
increases. For this reason, the liquid composition easily foams. To
prevent this, an anti-foaming agent is preferably used therein.
[0070] In the present embodiment, when the liquid composition
contains the fluorine-based surfactant, the surface tension of the
liquid composition is significantly reduced. In this case, usually
an anti-foaming agent, which is a component insoluble in liquid, is
used to intersperse this component in the surface of foams, to
thereby suppress foaming. However, such a component insoluble in
liquid degrades discharge stability and storage stability. In the
present embodiment, to prevent this problem, when the liquid
composition contains a fluorine-based surfactant, an anti-foaming
agent represented by Formula (6) is favorably used. The
anti-foaming agent represented by Formula (6) has high
compatibility with fluorine-based surfactants, and the anti-foaming
agent is efficiently incorporated into a foamed film. It can be
considered that for this reason, the surface of the foamed film is
locally in an imbalance condition due to a difference in surface
tension between the fluorine-based surfactant and the anti-foaming
agent, and foams are broken.
HOR.sub.1R.sub.3C--[CH.sub.2].sub.n--CR.sub.2R.sub.4OH Formula
(6)
[0071] in Formula (6), R.sub.1 and R.sub.2 each independently
denote an alkyl group having 3 to 6 carbon atoms; R.sub.3 and
R.sub.4 each independently denote an alkyl group having 1 to 2
carbon atoms; and n denotes an integer of 1 to 6.
[0072] The anti-foaming agent represented by Formula (6) is not
particularly limited and may be suitably selected in accordance
with the intended use. However, 2,4,7,9-tetramethyldecane-4,7-diol,
and 2,5,8,11-tetramethyldodecane-5,8-diol are preferable, and from
the viewpoints of anti-foaming effect and high solubility in the
liquid composition, 2,5,8,11-tetramethyldodecane-5,8-diol is
particularly preferable.
[0073] The amount of the anti-foaming agent contained in the liquid
composition is preferably 0.01% by mass to 10% by mass, and more
preferably 0.02% by mass to 5% by mass. When the amount of the
anti-foaming agent is less than 0.01% by mass, the anti-foaming
effect may not be sufficiently obtained. When it is more than 10%
by mass, the anti-foaming effect may not change even when the
addition amount thereof is increased, and the anti-foaming agent
may not be dissolved into the liquid composition.
[0074] The liquid composition of the present embodiment may contain
a known antiseptic agent, and a known anti-corrosive agent, etc.
used in a typical ink.
(Ink)
[0075] Next, a recording method of the present embodiment will be
described. The ink for use in the recording method of the present
embodiment contains negatively charged and colorant-containing
particles, and water. With this, the particles are dispersed in the
water and the like by electrostatic repulsion. The color of the ink
is not particularly limited and may be suitably selected in
accordance with the intended use. Examples thereof include yellow,
magenta, cyan, and black. When recording is performed using an ink
set in which two or more of these color inks, a color image can be
recorded. When recording is performed using an ink set which uses
at least three color inks in combination, a full color image can be
recorded.
[0076] The ink is suitably used in an inkjet recording method using
a recording apparatus such as a so-called piezo-type recording
apparatus (see Japanese Patent Application Laid-Open (JP-A) No.
02-51734), a so-called thermal type recording apparatus (see
Japanese Patent Application Laid-Open (JP-A) No. 61-59911), and a
so-called electrostatic type recording apparatus (see Japanese
Patent Application Laid-Open (JP-A) No. 06-71882). Also, the ink is
suitably used in a recording apparatus which heats a recording
medium and ink upon recording or before or after recording to
accelerate fixing of a recorded matter. Further, the ink is also
used in a recording apparatus which heats a recording medium and
ink upon recording or before or after recording to, for example,
from 50.degree. C. to 200.degree. C. to accelerate fixing of a
recorded matter.
[0077] Physical properties of the ink of the present embodiment are
not particularly limited and may be suitably selected in accordance
with the intended use. For example, the viscosity, and the surface
tension of the ink are each preferably within the following
ranges.
[0078] First, the viscosity of the ink at 25.degree. C. is
preferably 5 mPas to 20 mPas. By adjusting the viscosity of the ink
to 5 mPas or higher, the density and quality of an image to be
recorded can be improved. Meanwhile, by adjusting the viscosity of
the ink to 20 mPas or lower, excellent discharge stability can be
obtained. Here, the viscosity can be measured at 25.degree. C.
using a viscometer (e.g., RE-550L, manufactured by TOKI SANGYO Co.,
Ltd.).
[0079] The surface tension of the ink at 25.degree. C. is
preferably 20 mN/m to 35 mN/m, and more preferably 20 mN/m to 30
mN/m. When the surface tension of the ink is from 20 mN/m to 35
mN/m, the permeability of the ink is enhanced, and even when the
ink is recorded on plain paper, the drying properties are
excellent, to thereby suppress color bleeding. Further, the ink is
easily wet in a liquid composition-attached portion of a recording
medium i.e., a portion of a recording medium onto which the liquid
composition has been attached, the color saturation of a resulting
recorded matter is increased, and the resistance to white-out is
also improved. When the surface tension is higher than 35 mN/m, the
leveling of the ink (which means that an ink is uniformly spread on
a surface of a recording medium while wetting the surface thereof)
easily occurs on a recording medium, which may lead to lengthening
of duration for drying the ink.
[0080] Next, individual components contained in the ink will be
described.
<Colorant>
[0081] In the ink, as a water-dispersible colorant, a pigment is
mainly used from the standpoint of weatherability, however, to
control the color tone, a dye may be used in combination within a
range not degrading the weatherability. The pigment is not
particularly limited and may be suitably selected in accordance
with the intended use. For example, an inorganic pigment or organic
pigment for black color ink or an inorganic pigment or organic
pigment for color ink is used. These pigments may be used alone or
in combination. The amount of the colorant contained in the ink is
preferably, in terms of solid content, 2% by mass to 15% by mass,
and more preferably 3% by mass to 12% by mass. When the amount of
the colorant is less than 2% by mass, the color saturation and
image density of a resulting recorded matter may decrease. When the
amount of the pigment is more than 15% by mass, it is unfavorable
because the discharge stability may degrade due to the increased
viscosity of the ink.
[0082] Here, the solid content of the ink is measured, for example,
by a method of isolating only the water-dispersible colorant and
the water-dispersible resin fraction from the ink. In addition,
when a pigment is used as the water-dispersible colorant, a ratio
between the colorant and the water-dispersible resin is measured by
determining a mass reduction rate through thermal mass
spectrometry. When the molecular structure of the colorant is
clearly known, the solid content of a pigment or dye can be
determined using a specific wavelength of a spectrophotometer. As
for an inorganic pigment containing a heavy metal atom in a
molecular skeleton, a gold-containing organic pigment, and a
gold-containing dye, the solid content of the colorant can be
determined through X-ray fluorescence analysis.
[0083] As the inorganic pigment, there may be used an titanium
oxide, iron oxide, calcium carbonate, barium sulfate, aluminum
hydroxide, barium yellow, cadmium red and chrome yellow; and carbon
black produced by a conventionally known method such as a contact
method, a furnace method, a thermal method or the like.
[0084] As the organic pigment, there may be used azo pigments
(including azo lake, insoluble azo pigment, condensed azo pigment,
chelate azo pigment, etc.), polycyclic pigments (e.g.,
phthalocyanine pigment, perylene pigment, perynone pigment,
anthraquinone pigment, quinacridone pigment, dioxazine pigment,
indigo pigment, thioindigo pigment, isoindolinone pigment, and
quinophthalone pigment), dye chelates (e.g., basic dye-type
chelate, and acid dye-type chelate), nitro pigments, nitroso
pigments, and aniline black. Among these pigments, those having
excellent affinity with water are particularly preferably used.
[0085] Specific examples of preferably usable black color pigments
include carbon black (C.I. Pigment Black 7), such as furnace black,
lamp black, acetylene black, and channel black, or metals such as
copper, iron (C.I. Pigment Black 11), and titanium oxide, and
organic pigments such as aniline black (C.I. Pigment Black 1).
Specific examples of preferably usable color pigments include C.I.
Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, and 42 (yellow
iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 408,
109, 110, 117, 120, 128, 138, 150, 151, 153, 183, C.I. Pigment
Orange 5, 13, 16, 17, 36, 43, and 51, C.I. Pigment Red 1, 2, 3, 5,
17, 22, 23, 31, 38, 48:2, and 48:2 (Permanent Red 2B(Ca)), 48:3,
48:4, 49:1, 52:2, 53:1, and 57:1 (Brilliant Carmine 6B), 60:1,
63:1, 63:2, 64:1, 81, 83, 88, and 101 (colcothar), 104, 105, 106,
108 (Cadmium Red), 112, 114, 122 (quinacridone magenta), 123, 146,
149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, and
219, C.I. Pigment Violet 1 (Rhodamine Lake), 3, 5:1, 16, 19, 23,
and 38, C.I. Pigment Blue 1, 2, 15, 15:1, 15:2, 15:3
(phthalocyanine blue), 16, 17:1, 56, 60, 63, and C.I. Pigment Green
1, 4, 7, 8, 10, 17, 18, and 36.
[0086] In the present embodiment, the colorant is dispersed as
negatively charged particles in water. In this case, as a
sub-embodiment of dispersing the pigment in water, the following
first to third sub-embodiments described below are preferable.
[0087] In the first sub-embodiment, a dispersoid obtained by
incorporating a water-insoluble or sparingly water-soluble coloring
material into polymer fine particles (which may be referred to as
"a pigment coated with a resin") is dispersed in water serving as a
dispersion medium to produce a polymer emulsion (a water dispersion
of polymer fine particles containing a coloring material). Note
that in this case, the dispersoid contains solid fractions, and in
the present embodiment, this is referred to as "an emulsion".
[0088] In the second sub-embodiment, a pigment having at least one
hydrophilic group on its surface and showing water-dispersibility
in the absence of dispersants (the pigment is, otherwise, referred
to as "a self-dispersible pigment") is dispersed in water.
[0089] In the third sub-embodiment, a pigment is dispersed in water
using an anionic dispersant or a nonionic dispersant.
[0090] Examples of the polymer emulsion for use in the first
sub-embodiment include a polymer emulsion obtained by dispersing in
a dispersion medium a dispersoid in which a pigment is encapsulated
in polymer fine particles or a dispersoid in which a pigment is
adsorbed on surfaces of polymer fine particles. In this case, the
entire pigment is not necessarily encapsulated in or adsorbed onto
polymer fine particles, and it is allowable that the pigment is
dispersed in the emulsion within a range not impairing the effects
of the present embodiment. Examples of a polymer (polymer in
polymer fine particles) forming the polymer emulsion include
anionic vinyl polymers, polyester-based polymers, and
polyurethane-based polymers. Particularly preferably usable
polymers are vinyl-based polymers and polyester-based polymers.
Polymers disclosed in Japanese Patent Application Laid-Open (JP-A)
Nos. 2000-53897, 2001-139849 and the like can be used.
[0091] The self-dispersible pigment according to the second
sub-embodiment is a pigment in which at least one hydrophilic group
is bonded, directly or via another atomic group, to a surface of a
pigment to modify the surface of the pigment. To modify the surface
of the pigment, there may be used a method in which a predetermined
anionic functional group (a functional group such as a sulfone
group and a carboxyl group) is chemically bonded to a surface of a
pigment, or a method in which a pigment is subjected to a
wet-process oxidation treatment using at least one of a hypohalous
acid, such as hypochlorous acid or a salt thereof. Among these
methods, particularly preferred is a sub-embodiment in which a
carboxyl group is bonded to a surface of a pigment and the pigment
is dispersed in water. When a carboxyl group is bonded to a surface
of a pigment, not only the dispersion stability of the pigment is
improved, but also a high quality image can be obtained, and the
water resistance of a resulting recorded recording medium is more
improved. Further, an ink containing the self-dispersible pigment
according to the second sub-embodiment is excellent in
re-dispersibility after drying, and even when recording is stopped
for a long period of time and the water content of the ink filled
in a nozzle in a recording apparatus is evaporated, excellent
recording can be easily performed with a simple cleaning operation,
without causing nozzle clogging. To obtain such properties, the
volume average particle diameter (D.sub.50) of the self-dispersible
pigment in the ink is preferably 0.01 .mu.m to 0.16 .mu.m. Here,
"D.sub.50" is also called a median diameter, and means a diameter
of particles by which the particles are divided into two groups,
and an amount of the large group and an amount of the small group
are equal (for example, such as volume average particle diameter).
Note that, in the present embodiment, when a self-dispersible
pigment according to the second sub-embodiment is used, the ink
preferably contains a water-dispersed resin, which will be
described below, for improving the fixability (abrasion resistance)
of the coloring material on a recording medium and improving the
color-developing ability.
[0092] When the self-dispersible pigment is a self-dispersible
carbon black, as an anionic functional group to be bonded to the
carbon black, --COOM, --SO.sub.3M, --PO.sub.3HM, --PO.sub.3M.sub.2,
--SO.sub.2NH.sub.2, and --SO.sub.2NHCOR (where M denotes an alkali
metal, ammonium or organic ammonium; and R denotes an alkyl group
having 1 to 12 carbon atoms, a phenyl group that may have a
substituent or a naphthyl group that may have a substituent.) may
be used. Among these, --COOM, and --SO.sub.3M are preferable.
[0093] When "M" in the above-mentioned anionic functional group is
an alkali metal, for example, lithium, sodium, or potassium is used
as the alkali metal. When "M" is organic ammonium, for example,
mono-, dim-, and tri-methyl ammonium, mono-, di-, and tri-ethyl
ammonium, or mon-, dim-, and tri-methanol ammonium may be used as
the organic ammonium. The anionic functional group may be bonded to
a surface of carbon black via other atomic groups. Examples of the
other atomic groups include an alkyl group having 1 to 12 carbon
atoms, a phenyl group that may have a substituent or a naphthyl
group that may have a substituent. Specific examples of the
functional group to be bonded on a surface of carbon black via
other atomic groups include --C.sub.2H.sub.4COOM (where M denotes
an alkali metal or quaternary ammonium.), and -PhSO.sub.3M (where
Ph denotes a phenyl group; and M denotes an alkali metal or
quaternary ammonium.).
[0094] When the self-dispersible pigment is a color pigment, in
order to obtain a color pigment having the above-mentioned anionic
functional group, the above-mentioned anionic functional group
(e.g., --COONa) can be introduced into the color pigment by a
method in which the color pigment is subjected to an oxidation
treatment using hypochlorous acid soda, a method of sulfonating the
color pigment, a method of reacting a diazonium salt with the color
pigment or the like.
[0095] In the third sub-embodiment, the above-mentioned pigment is
dispersed in water by an anionic dispersant or a nonionic
dispersant.
[0096] Examples of the anionic dispersant include polyoxyethylene
alkylether acetate, an alkylbenzene sulfonic acid salt (NH.sub.4,
Na, Ca), an alkyldiphenylether disulfonic acid salt (NH.sub.4, Na,
Ca), a sodium salt of dialkylsuccinate sulfonate, a sodium salt of
a naphthalene sulfonate-formalin condensate, an ester salt of a
polyoxyethylene polycyclic phenylether sulfate (NH.sub.4, Na), a
lauric acid salt, a sulfate salt of polyoxyethylene alkylether, and
an oleic acid salt. Among these, a sodium salt of dioctyl
sulfosuccinate, and an ammonium salt of polyoxyethylene styrene
phenylether sulfonate are particularly preferable.
[0097] As the nonionic surfactant, a nonionic surfactant having an
HLB value of 10 to 20 is preferable. Examples thereof include
polyoxyethylene alkylether, polyoxyalkylene alkyl ether,
polyoxyethylene polycyclic phenyl ether, sorbitan fatty acid ester,
polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl
phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl
amide, and acetylene glycol. Among these, polyoxyethylene lauryl
ether, polyoxyethylene-.beta.-naphthylether, polyoxyethylene
sorbitan monooleate, and polyoxyethylene styrene phenyl ether are
particularly preferable. Note that, when a nonionic dispersant is
used, the entire system of the ink can also be negatively charged
by using a negatively charged resin emulsion in combination with
the nonionic dispersant.
[0098] In the third sub-embodiment, the pigment dispersion is
produced in the following method. First, the above-mentioned
pigment dispersant is dissolved in an aqueous medium. Next, the
organic pigment or the inorganic pigment is added thereto, and the
system is sufficiently wetted, followed by high-speed stirring
through use of a homogenizer, or stirring and dispersing through
use of a dispersing machine using a ball such as a bead mill and a
ball mill, a dispersion kneader using a shearing force such as a
roll mill, a ultrasonic wave dispersing machine, or the like. In
most cases, coarse particles are contained in the resulting pigment
dispersion after such a kneading/dispersing step. This causes
nozzle clogging and/or clogging of an ink-supply channel in a
recording apparatus, and thus there is a need to remove particles
each having a particle diameter of 1 .mu.m or greater using a
filter or a centrifugal separator.
[0099] In the present embodiment, it is preferable that the
dispersant be used in an amount of 1 part by mass to 100 parts by
mass, and more preferably in an amount of 10 parts by mass to 50
parts by mass, relative to 100 parts by mass of the pigment. When
the amount of the dispersant is small, it is impossible to form the
pigment into sufficiently fine particles. When the amount of the
dispersant is excessively large, excess components of the
dispersant not adsorbed on the pigment adversely affect physical
properties of the resulting ink, which may cause ink bleeding, and
degradation of water resistance and abrasion resistance of an image
to be recorded. Note that in the present embodiment, when the
self-dispersible pigment according to the third sub-embodiment is
used, the ink preferably contains a water-dispersed resin, which
will be described below, for improving the fixability (abrasion
resistance) of the coloring material on a recording medium and
improving the color-developing ability.
[0100] Further, to stabilize the pigment dispersion, a
water-soluble polymer compound having a weight average molecular
weight of 30,000 or lower may be used in combination. As the
water-soluble polymer compound, generally, a water-soluble
styrene-acrylic resin, a water-soluble acrylic resin, water-soluble
polyurethane, water-soluble polyester, water-soluble styrene-maleic
acid copolymer, and water-soluble .alpha.-olefin-maleic acid
copolymer each having a weight average molecular weight of 30,000
or lower are preferable. Among these, water-soluble polyurethane
and water-soluble polyester each having a weight average molecular
weight of 30,000 or lower, and a water-soluble
.alpha.-olefin-maleic acid copolymer represented by Formula (7) are
particularly preferable.
##STR00008##
[0101] in Formula (7), R denotes an alkyl group having 6 to 22
carbon atoms, and n denotes an integer of about 30 to about
100.
[0102] The acid value of the water-soluble .alpha.-olefin-maleic
acid copolymer represented by Formula (7) is preferably 100 mgKOH/g
to 400 mgKOH/g. When the acid value is lower than 100 mgKOH/g, the
solubility of the pigment dispersion may degrade. On the other
hand, when the acid value is higher than 400 mgKOH/g, the viscosity
of the pigment dispersion increases, and there is a possibility
that the ink-discharge properties easily degrade and the dispersion
stability of the pigment dispersion easily degrades. The weight
average molecular weight of the water-soluble .alpha.-olefin-maleic
acid copolymer represented by Formula (7) is preferably 5,000 to
20,000. When the weight average molecular weight is lower than
5,000, the dispersion stability of the pigment dispersion may
degrade. On the other hand, when the weight average molecular
weight is higher than 20,000, the solubility of the pigment
dispersion may degrade, and the viscosity thereof may increase.
[0103] The amount of the water-soluble polymer compound contained
in the pigment dispersion (in terms of solid content) is preferably
1 part by mass to 100 parts by mass, and more preferably 5 parts by
mass to 50 parts by mass, relative to 100 parts by mass of the
pigment. When the amount of the water-soluble polymer compound is
less than 1 part by mass, the effect of improving the dispersion
stability may be insufficient. On the other hand, when the amount
of the water-soluble polymer compound is higher than 100 parts by
mass, the viscosity of the ink increases, the discharge stability
thereof may degrade, and it may make no difference in the effect of
improving the dispersion stability even when the amount thereof is
increased.
[0104] The volume average particle diameter (D.sub.50) of the
pigment of the present embodiment is preferably 150 nm or smaller
in an ink, and more preferably 100 nm or smaller. When the volume
average particle diameter (D.sub.50) of the pigment is greater than
150 nm, the discharge stability of the resulting ink rapidly
degrades, and nozzle clogging and ink ejection deviation easily
occur. On the other hand, when the volume average particle diameter
(D.sub.50) is 100 nm or smaller, the discharge stability is
improved, and the color saturation of an image is also improved.
The amount of the pigment in the ink is preferably 1% by mass to
15% by mass, and more preferably 2% by mass to 12% by mass.
Moreover, the polymer emulsion according to the first
sub-embodiment in which a pigment is coated with anionic polymer
fine particles, and the self-dispersible pigment according to the
second sub-embodiment, and the water-dispersible colorant according
to the third sub-embodiment may be used in combination in the form
of a mixture.
<Water-Soluble Organic Solvent>
[0105] A water-soluble organic solvent for use in the ink is not
particularly limited, however, a similar water-soluble organic
solvent to that used in the above-described liquid composition is
preferably used. The mass ratio of the water-dispersible colorant
to the water-soluble organic solvent in the ink influences the
discharge stability of the ink discharged from an inkjet head. For
example, when the amount of the water-soluble organic solvent is
small although the solid content of the water-dispersible colorant
is high, evaporation of water present in the vicinity of an ink
meniscus of a nozzle may proceed to cause a discharge defect. The
amount of the water-soluble organic solvent contained in the ink is
preferably 20% by mass to 50% by mass, and more preferably 20% by
mass to 45% by mass. When the amount of the water-soluble organic
solvent is less than 20% by mass, there is a possibility that the
discharge stability degrades and a waste ink adheres to a
maintenance device in a recording apparatus. When the amount of the
water-soluble organic solvent is more than 50% by mass, the drying
properties thereof may degrade on a paper surface, and the quality
of a recorded matter may further degrade.
<Surfactant>
[0106] As a surfactant for use in the ink, a similar surfactant to
that used in the liquid composition of the present embodiment is
preferably used. Among these preferably usable surfactants, it is
preferable to select a surfactant having low surface tension and
high permeability and high leveling properties, without impairing
the dispersion stability of the pigment dispersion depending on the
type of the water-dispersible colorant and combination of the
water-soluble organic solvent with the surfactant. Specifically, at
least one selected from an anionic surfactant, a nonionic
surfactant, a silicone-based surfactant and a fluorine-based
surfactant is preferably used. Among these, a silicone-based
surfactant and a fluorine-based surfactant are particularly
preferably used. These surfactants may be used alone or in
combination. The amount of the surfactant contained in the ink is
preferably 0.01% by mass to 3.0% by mass, and more preferably 0.5%
by mass to 2% by mass. When the amount of the surfactant is less
than 0.01% by mass, the effect obtained when adding the surfactant
may be insufficient, and whereas, when it is more than 3.0% by
mass, the permeability of the ink to a recording medium is
increased more than necessary, the image density of a recorded
image may degrade, and strikethrough (this means that the ink
attached to a recording medium penetrates through the recording
medium and an recorded image is distinguished from the rear surface
of the recorded image) may occur.
<Penetrant>
[0107] A penetrant for use in the ink, a similar penetrant to that
used in the liquid composition of the present embodiment is
preferably used. The amount of the penetrant contained in the ink
is preferably 0.1% by mass to 4.0% by mass. When the amount of the
penetrant is less than 0.1% by mass, the drying properties of the
ink degrades, and bleeding may occur in a recorded image. When the
amount of the penetrant is more than 4.0% by mass, the dispersion
stability of the colorant is impaired, nozzle clogging may easily
occur in a recording apparatus, and the permeability of the ink to
a recording medium is increased more than necessary, which may
cause a decrease in image density of a recorded matter and
strikethrough.
<Water-Dispersible Resin>
[0108] The above-mentioned water-dispersible resin is formed into a
film on a recorded matter onto which the ink has been made to
adhere, and is used for improving the water repellency, water
resistance and weatherability of a recorded image and improving the
image density and color saturation thereof. Examples of this
water-dispersible resin include condensed type synthetic resins,
addition type synthetic resins, and natural polymer compounds.
[0109] Examples of the condensed type synthetic resins include
polyester resins, polyurethane resins, polyepoxy resins, polyamide
resins, polyether resins, poly(meth)acrylic resins, acryl-silicone
resins, and fluorine-based resins.
[0110] Examples of the addition type synthetic resins include
polyolefin resins, polystyrene-based resins, polyvinyl
alcohol-based resins, polyvinyl ester-based resins, polyacrylic
acid-based resins, and unsaturated carboxylic acid-based
resins.
[0111] Examples of the natural polymer compounds include
celluloses, rosins, and natural rubbers.
[0112] Among these, polyurethane resin fine particles,
acryl-silicone resin fine particles, and fluorine-based resin fine
particles are particularly preferable. These water-dispersible
resins may be used in combination.
[0113] Here, as for the fluorine-based resin fine particles,
fluorine-based resin fine particles having a fluoroolefin unit are
preferable. Among these, fluorine-containing vinylether-based resin
fine particles composed of a fluoroolefin unit and a vinylether
unit are particularly preferable. The fluoroolefin unit is not
particularly limited and may be suitably selected in accordance
with the intended use. Examples thereof include divalent
fluoroolefin groups, such as --CF.sub.2CF.sub.2--,
--CF.sub.2CF(CF.sub.3)--, and --CF.sub.2CFCl--. The vinylether unit
is not particularly limited and may be suitably selected in
accordance with the intended use. Examples thereof include
compounds represented by each of the following structural
formula.
##STR00009##
[0114] As for the fluorine-containing vinylether-based resin fine
particles composed of a fluoroolefin unit and a vinylether unit, an
alternate copolymer in which a fluoroolefin unit and a vinylether
unit are alternately copolymerized is preferable. As such
fluorine-based resin fine particles, suitably synthesized one and a
commercially available product may be used. Examples of the
commercially available products include FLUONATE FEM-500 and
FEM-600, DICGUARD F-52S, F-90, F-90M, F-90N and AQUAFURAN TE-5A
manufactured by DIC Corporation; LUMIFLON FE4300, FE4500, FE4400,
ASAHI GUARD AG-7105, AG-950, AG-7600, AG-7000, and AG-1100
manufactured by Asahi Glass Co., Ltd.
[0115] As for the water-dispersible resin, both a homopolymer and a
composite resin made of a copolymer may be used, and any of a
single-phase structured type emulsion, a core-shell type emulsion
and a power-feed type emulsion may be used.
[0116] As the water-dispersible resin, a water-dispersible resin in
which a resin itself has a hydrophilic group and
self-dispersibility and a water-dispersible resin in which a resin
itself does not have dispersibility and to which the dispersibility
is imparted by a surfactant and a resin having a hydrophilic group
are used. Among these, an emulsion of resin particles obtained by
emulsification or suspension polymerization of an ionomer of a
polyester resin, a polyurethane resin or an unsaturated monomer is
preferably used. Here, when an unsaturated monomer is emulsion
polymerized, a water-dispersible resin is easily produced because a
resin emulsion is obtained by reacting water into which the
unsaturated monomer, a polymerization initiator, a surfactant, a
chain transfer agent, a chelating agent, a pH adjustor etc. have
been added. In this case, a water-dispersible resin having intended
physical properties can be easily produced because components
constituting the resin are easily changed.
[0117] As for the unsaturated monomer, unsaturated carboxylic
acids, monofunctional or polyfunctional (meth)acrylic acid ester
monomers, (meth)acrylic acid amide monomers, aromatic vinyl
monomers, vinyl cyano compound monomers, vinyl monomers, allyl
compound monomers, olefin monomers, diene monomers, oligomers
having an unsaturated carbon etc. can be used alone or in
combination. The physical properties of a water-dispersible resin
produced can be easily changed by using these monomers in
combination. Further, the physical properties of the resin can also
be modified by subjecting the components to a polymerization
reaction or graft reaction using an oligomer type polymerization
initiator as a polymerization initiator.
[0118] Examples of the unsaturated carboxylic acids serving as the
unsaturated monomer include an acrylic acid, methacrylic acid,
itaconic acid, fumaric acid, and maleic acid.
[0119] Examples of the monofunctional (meth)acrylic acid ester
monomers include methyl methacrylate, ethyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl
methacrylate, isoamyl methacrylate, n-hexyl methacrylate,
2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate,
dodecyl methacrylate, octadecyl methacrylate, cyclohexyl
methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl
methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl
methacrylate, dimethyl aminoethyl methacrylate, methacryloxy ethyl
trimethyl ammonium salts, 3-methacryloxypropyl trimethoxysilane,
methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl
acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate,
n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl
acrylate, dodecyl acrylate, octadecyl acrylate, cyclohexyl
acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dimethyl
aminoethyl acrylate, and acryloxy ethyl trimethyl ammonium
salts.
[0120] Examples of the polyfunctional (meth)acrylic acid ester
monomers include ethylene glycol dimethacrylate, diethylene glycol
dimethacrylate, triethylene glycol dimethacrylate, polyethylene
glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate,
neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate,
polypropylene glycol dimethacrylate, polybutylene glycol
dimethacrylate, 2,2'-bis(4-methacryloxydiethoxyphenyl)propane,
trimethylol propane trimethacrylate, trimethylol ethane
trimethacrylate, polyethylene glycol diacrylate, triethylene glycol
diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol
diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate,
1,9-nonanediol diacrylate, polypropylene glycol diacrylate,
2,2'-bis(4-acryloxypropyloxyphenyl)propane,
2,2'-bis(4-acryloxydiethoxyphenyl)propane trimethylol propane
triacrylate, trimethylolethane triacrylate, tetramethylolmethane
triacrylate, ditrimethylol tetraacrylate, tetramethylol methane
tetraacrylate, pentaerythritol tetraacrylate, and dipentaerythritol
hexaacrylate.
[0121] Examples of the (meth)acrylic acid amide monomers include
acrylamide, methacrylamide, N,N-dimethyl acrylamide, methylene
bis-acrylamide, and 2-acrylamide-2-methylpropane sulfonic acid.
Examples of the aromatic vinyl monomers include styrene,
.alpha.-methylstyrene, vinyl toluene, 4-t-butylstyrene,
chlorostyrene, vinyl anisole, vinyl naphthalene, and divinyl
benzene.
[0122] Examples of the vinyl cyano compound monomers include
acrylonitrile, and methacrylonitrile.
[0123] Examples of the vinyl monomers include vinyl acetate,
vinylidene chloride, vinyl chloride, vinyl ether, vinyl ketone,
vinyl pyrrolidone, vinyl sulfonic acid or salts thereof, vinyl
trimethoxysilane, and vinyl triethoxysilane.
[0124] Examples of the allyl compound monomers include
allylsulfonic acid or salts thereof, allylamine, allyl chloride,
diallylamine, and diallyldimethyl ammonium salts.
[0125] Examples of the olefin monomers include ethylene, and
propylene.
[0126] Examples of the diene monomers include butadiene, and
chloroprene.
[0127] Examples of the oligomers having an unsaturated carbon
include styrene oligomers each having a methacryloyl group,
styrene-acrylonitrile oligomers each having a methacryloyl group,
methyl methacrylate oligomers each having a methacryloyl group,
dimethyl siloxane oligomers each having a methacryloyl group, and
polyester oligomers each having an acryloyl group.
[0128] Since a water-dispersible resin undergoes dispersion
breaking and breaking of molecular chains due to hydrolysis, under
a strong alkaline or strong acidic condition, the pH of the
water-dispersible resin before being added into an ink is
preferably 4 to 12. Particularly, from the standpoint of
miscibility with a water-dispersible colorant, the pH is more
preferably 6 to 11, and still more preferably 7 to 9. The average
particle diameter (D.sub.50) of the water-dispersible resin relates
to the viscosity of the dispersion liquid. When water-dispersible
resins having the same composition and the same concentration of
solid content, the smaller the particle diameter, the higher the
viscosity is. Therefore, the average particle diameter (D.sub.50)
of the water-dispersible resin is preferably 50 nm or greater so
that the viscosity of the resulting ink is not excessively high.
When the particle diameter of the water-dispersible resin is
several ten micrometers, it is greater than the diameter of a
nozzle of an inkjet head in a recording apparatus. When such
particles having large particle diameters are present in the
resulting ink, the discharge stability of the ink degrades. Then,
to secure the discharge stability of the ink, the average particle
diameter (D.sub.50) of the water-dispersible resin is preferably
200 nm or smaller, and more preferably 150 nm or smaller.
[0129] Further, since the water-dispersible resin has a function to
fix a water-dispersible colorant on a recording medium, it is
preferable to form it into a film at normal temperature. For this
reason, the minimum film-forming temperature (MFT) of the
water-dispersible resin is preferably 30.degree. C. or lower. In
addition, when the glass transition temperature of the
water-dispersible resin is lower than -40.degree. C., the
consistency of the resin film is higher, and tacking (which means
stickiness, and viscosity) may occur on a recorded matter. For this
reason, the glass transition temperature of the water-dispersible
resin is preferably -40.degree. C. or higher, and more preferably
-30.degree. C. or higher. The amount of the water-dispersible resin
contained in the ink is preferably 1% by mass to 15% by mass, and
more preferably 2% by mass to 7% by mass, in terms of solid
content.
<Other Components>
[0130] Next, other components that can be added to an ink used in
the recording method of the present embodiment will be described.
Such other components are not particularly limited and may be
suitably selected as required. Examples thereof include a pH
adjustor, an antiseptic-antifungal agent, a chelating reagent, an
anti-corrosive agent, an antioxidant, a ultraviolet absorber, an
oxygen absorbent, and a light stabilizer.
<<pH Adjustor>>
[0131] The pH adjustor is not particularly limited, as long as it
can adjust the pH of an ink formulated to 7 to 11 without adversely
affecting the ink, and may be suitably selected in accordance with
the intended use. When the pH of the ink is lower than 7 or higher
than 11, the ink may dissolve a head or ink-supplying unit of a
recording device to thereby change the properties of the ink or to
cause leakages of the ink, which may cause problems such as
discharge defect. Examples of the pH adjustor preferably used in
the present embodiment include alcohol amines, hydroxides of alkali
metal elements, ammonium hydroxides, phosphonium hydroxides, and
carbonates of alkali metals.
[0132] Examples of the alcohol amines include diethanolamine,
triethanolamine, and 2-amino-2-ethyl-1,3-propane diol. Examples of
the hydroxide of alkali metal element include lithium hydroxides,
sodium hydroxides, and potassium hydroxides. Examples of the
hydroxide of ammonium include ammonium hydroxides, quaternary
ammonium hydroxides, and quaternary phosphonium hydroxides.
Examples of the carbonate of alkali metal include lithium
carbonates, sodium carbonates, and potassium carbonates.
<<Antiseptic-Antifungal Agent>>
[0133] As the antiseptic-antifungal agent, sodium dehydroacetate,
sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate,
sodium pentachlorophenol, a 1,2-benzoisothiazoline-3-on sodium
compound, and the like are suitably used.
<<Chelating Reagent>>
[0134] As the chelating reagent, sodium ethylenediamine
tetraacetate, sodium nitrilo triacetate, sodium hydroxyethyl
ethylenediamine triacetate, sodium diethylene triamine
pentaacetate, sodium uramil diacetate, and the like are suitably
used.
<<Anti-Corrosive Agent>>
[0135] As the anti-corrosive agent, acid sulfite, sodium
thiosulfate, ammonium thiodiglycolate, diisopropyl ammonium
nitrite, pentaerythritol tetranitrate, dicyclohexyl ammonium
nitrite, 1,2,3-benzotriazole, and the like are suitably used.
<<Anti-Oxidant>>
[0136] As the anti-oxidant, phenol-based anti-oxidants (including
hindered phenol-based anti-oxidants), amine-based anti-oxidants,
sulfur-based anti-oxidants, phosphorous-based anti-oxidants, and
the like are suitably used.
<<Ultraviolet Absorbent>>
[0137] As the ultraviolet absorbent, benzophenone-based ultraviolet
absorbents, benzotriazole-based ultraviolet absorbents,
salicylate-based ultraviolet absorbents, cyanoacrylate-based
ultraviolet absorbents, nickel complex salt-based ultraviolet
absorbents, and the like are suitably used.
[Ink Production Method]
[0138] An ink is produced by dispersing or dissolving, in an
aqueous medium, a water-dispersible colorant, a water-soluble
organic solvent, a surfactant, a penetrant and water, and further,
if necessary, other components and further, as required, by
stirring and mixing these components. The stirring and mixing can
be perfumed by a sand mill, a homogenizer, a ball mill, a paint
shaker, an ultrasonic dispersing machine or the like, and also
performed by a stirrer using stirring blades, a magnetic stirrer, a
high-speed dispersing machine or the like.
(Recording Medium)
[0139] As a recording medium for use in the recording method of the
present embodiment, plain paper having no coating layer is
preferably used. In particular, the recording medium is preferably
plain paper having a sizing degree (JIS P8122) of 10S or higher and
an air permeability (JIS P8117) of 5S to 50S, which is used for
copy paper and the like.
(Recording Method)
[0140] Hereinafter, a recording method according to the present
invention will be further described by way of preferred
embodiments. A recording method of the present embodiment includes
making the liquid composition of the present embodiment adhere onto
a recording medium, and making an ink adhere to the recording
medium onto which the liquid composition has been made to adhere.
Each of these steps will be described hereinbelow.
<Step of Making Liquid Composition Adhere onto Recording
Medium>
[0141] The step of making the liquid composition adhere onto a
recording medium is not particularly limited, and a method may be
used in which the liquid composition of the present embodiment is
uniformly applied to a surface of a recording medium so that the
liquid composition is attached thereon. Examples of such a method
include a blade coating method, a gravure coating method, a gravure
offset coating method, a bar coating method, a roll coating method,
a knife coating method, an air-knife coating method, a comma
coating method, a U-comma coating method, an AKKU coating method, a
smoothing coating method, a micro gravure coating method, a reverse
roll coating method, coating method using four rollers or five
rollers, a dip coating method, a curtain coating method, a slide
coating method, and a die coating method.
[0142] The wet adhesion amount of the liquid composition to the
recording medium (i.e., an adhesion amount of the liquid
composition before a recording medium is dried) in the step of
making the liquid composition adhere onto a recording medium is
preferably 0.1 g/m.sup.2 to 30.0 g/m.sup.2, and more preferably 0.2
g/m.sup.2 to 10.0 g/m.sup.2. When the wet adhesion amount is less
than 0.1 g/m.sup.2, the image quality (image density, color
saturation, color bleeding, and feathering) of a recorded matter
may not be improved. When the wet adhesion amount is more than 30.0
g/m.sup.2, the texture of a recorded matter may be impaired and
curling may occur. Note that, if necessary, a drying step may be
provided to dry the recording medium onto which the liquid
composition has been made to adhere. In this case, the recording
medium may be dried by a roll heater, a drum heater, or hot
air.
<Step of Making Ink Adhere onto Recording Medium>
[0143] The step of making an ink adhere onto a recording medium in
the recording method of the present embodiment is a step in which
an ink is applied to the recording medium onto which the liquid
composition of the present embodiment has been made to adhere so
that the ink is attached thereon, and thereby recording an image on
the recording medium. The method of making an ink adhere onto a
recording medium is not particularly limited and may be suitably
selected in accordance with the intended use. Examples thereof
include a method in which an impulse (energy) is applied to an ink
by a predetermined device to discharge the ink so as to make the
ink adhere onto the recording medium. More specifically, any known
inkjet recording methods can be employed. Examples of such inkjet
recording methods include an inkjet recording method through
scanning with an inkjet recording head, and an inkjet recording
method in which an image is recorded on a certain sheets of
recording media by using a line-type inkjet recording head.
[0144] In the step of making the ink adhere to the recording
medium, the driving method of a recording head serving as a unit of
discharging an ink is not particularly limited, and may be suitably
selected in accordance with the intended use. Examples of the
driving method include a method of operating or using a
piezoelectric element actuator using PZT (lead zirconate titanate)
or thermal energy; a method of using an on-demand-type recording
head using an actuator utilizing an electrostatic force; and a
recording method using a continuous jetting type-charge
controllable head. In the method of operating heat energy, it is
said to be difficult to control the jetting of liquid droplets as
desired, and the quality of images recorded is prone to
significantly vary depending on the type of a recording medium
used. This problem is, however, resolved by giving the liquid
composition to the recording medium, and it is possible to obtain a
stable and high quality recorded matter irrespective of the type of
the recording medium used. Note that the step of making an ink
adhere onto a recording medium exhibits its effect to a recording
medium on which surface has been sufficiently dried as well as to a
recording medium on which surface has not been dried.
(Recording Apparatus)
[0145] A recording apparatus for recording an image by applying the
liquid composition to a recording medium and applying an ink to the
recording medium with the liquid composition having adhered to a
surface thereof to thereby record an image on the recording medium
will be described with reference to a specific example illustrated
in FIG. 2. The recording apparatus illustrated in FIG. 2 is a
recording apparatus which records an image by scanning the inkjet
recording head. In the recording apparatus illustrated in FIG. 2, a
recording medium 6 is sent out by a paper-feed roller 7, and a
liquid composition 1 is uniformly and thinly applied onto the
recording medium 6 by an applying roller 4 and a counter roller 5.
The liquid composition 1 is pumped up by a pump-up roller 3 and
uniformly applied to the applying roller 4 by a film thickness
controlling roller 2. The recording medium 6 onto which the liquid
composition 1 has been applied is then fed to a recording-scanning
section where an inkjet recording head 20 is present. Since the
length of a paper conveyance route from an end portion (A portion
in FIG. 2) of the operation of applying the liquid composition to a
start portion (B portion in FIG. 2) of recording-scanning is
designed to be longer than the length of the recording medium in
the feeding direction, application of the liquid composition can be
finished at the point where the recording medium reaches the start
portion of recording-scanning. In this case, since application of
the liquid composition can be carried out before the inkjet
recording head 20 starts scanning for recording and the recording
medium 6 is intermittently conveyed, the liquid composition can be
continuously applied to the recording medium 6 in a state where the
conveyance speed of the recording medium 6 is constant and
uniformly applied thereto without nonuniformity. Note that the
recording apparatus example illustrated in FIG. 2 is configured so
that the recording medium 6 onto which the liquid composition is
necessary to be applied is supplied from a lower cassette, and
other recording media 17 are supplied from an upper cassette, and
thus this is advantageous to provide a longer conveyance route for
a recording medium.
[0146] FIG. 3 illustrates another example of the recording
apparatus of the present embodiment. An exemplary recording
apparatus illustrated in FIG. 3 is also a recording apparatus which
records by scanning an inkjet recording head, and this recording
apparatus is designed in more compact than the recording apparatus
illustrated in FIG. 2. A recording medium 17 is sent out by a paper
feeding roller 18, and a liquid composition 1 is uniformly applied
in a thin thickness to the recording medium 17 by an applying
roller 4 and a counter roller 5. The liquid composition 1 is pumped
up by a pump-up roller 3 and uniformly applied to the applying
roller 4 by a film thickness control roller 2. The recording medium
17 passes a recording-scanning portion where an inkjet recording
head 20 is present while being applied thereto, and fed until the
application of the liquid composition 1 to the recording medium 17
is completed. At the time when the application is completed, the
recording medium 17 is returned back again until a tip portion
thereof reaches a recording-scanning start portion. The completion
of the application is detected by proving a known recording
medium-detection unit (not illustrated) in the vicinity of the
outlet of a liquid composition applying unit in the recording
apparatus. This detection unit is not necessarily provided to the
recording apparatus, and the recording apparatus may be
systematically configured so that the feed amount of the recording
medium 17 along the outer peripheral of the conveyance roller
corresponds to the length of the recording medium 17 by
preliminarily inputting information on the length of the recording
medium 17 in a controller and controlling the number of revolutions
of the motor.
[0147] When double-sided recording is performed, the recording
medium 17 onto which the liquid composition 1 has been applied is
conveyed again to the recording-scanning portion before the liquid
composition is dried and solidified. At this point in time, the
recording medium 17 is intermittently conveyed in synchronization
with scanning of the inkjet recording head 20. When the recording
medium 17 is made returned to the same route as that it is sent
from first, the rear end of the recording medium 17 reversely
enters to the liquid composition applying device. This causes
failures such as coating nonuniformity, smear, and jamming of the
recording medium 17. When the recording medium 17 is made returned
back, the direction thereof is switched by a recording medium guide
31. That is, when the recording medium 17 is sent in the reverse
direction after the liquid composition 1 is applied to the
recording medium 17, the recording medium guide 31 is moved to a
portion indicated by a dotted line in the figure by a known unit
such as a soleide and a motor. With this, the recording medium 17
is conveyed to the position of a recording medium return guide 34,
and thus it is possible to prevent occurrence of smear and jamming
of the recording medium.
[0148] The step of making the liquid composition adhere to the
recording medium is preferably performed at a constant linear speed
of 10 mm/s to 1,000 mm/s. Therefore, in this exemplary recording
apparatus, using sheets of a recording medium, when focused on a
certain recording medium sheet, after the process of applying the
liquid composition onto the recording medium is finished for the
certain recording medium sheet, a process of making an ink adhere
to a surface thereof and image processing is started. In such a
recording apparatus, in most cases, the speed of applying a liquid
composition is inconsistent with the speed of recording an image,
and thus there is a time lag between a recording start portion and
a recording end portion of recording sheets of paper, from the time
when the liquid composition is applied to the recording medium to
the time when the image is recorded. Even when the time lag is
significant, in a liquid composition which contains a water-soluble
organic solvent having a boiling point higher than that of water
and low evaporation speed, and in which the water content ratio is
adjusted so as to be an amount nearly in equilibrium with the water
content in air under an environment a printer is used, evaporation
of water is remarkably suppressed. Thus, a difference in image
quality caused between a recording start portion and a recording
end portion can be reduced to the level where it can be, at least,
visually observed.
[0149] As clearly understood from the conveyance step of a
recording medium in this recording apparatus, in most cases, there
is a need to convey a recording medium to which a liquid
composition is applied, through use of a unit for contacting the
recording medium, such as a roller, a small roller, and guide. In
this case, when the liquid composition having adhered to the
recording medium is transferred to conveyance members, it may cause
problems, for example, failures occur in the conveyance function,
and smear is accumulated to cause degradation in quality of images.
In this case, the occurrence of such problems is reduced by
providing a wavy plate guide in a recording medium, providing a
spur-shaped small roller, and/or using a water-repellent material
for a roller surface.
[0150] To control the operation of a recording apparatus as
illustrated in FIGS. 2 and 3, when a recording apparatus receives a
printing direction from a host machine such as a personal computer,
the recording apparatus starts a head cleaning work and a liquid
composition applying work simultaneously, and at the time all
preparations have finished, it starts recording operation. In this
case, the transfer of image data may be even for one time scanning,
even for a plurality of scanning times or even for one page. The
operations of the head cleaning and ink jetting check are not
necessarily required. In addition, the operations of head cleaning
and ink jetting check and the image data processing and transfer of
image data are not necessarily sequentially performed. It is
possible for the recording apparatus to perform these operations in
parallel, for example, the operations of coating of the liquid
composition, head cleaning and ink jetting check and the image data
processing and transfer of image data are made to start at the same
time. In this way, by performing these processes in parallel, it is
possible to record an image without substantially decreasing the
through-put of the recording apparatus even when the recording
apparatus (liquid composition applying unit) performs application
of the liquid composition.
<<Supplemental Description>>
[0151] In the recording method of the above-mentioned embodiment, a
predetermined ink is made to adhere on a recording medium onto
which a predetermined liquid composition has been made to adhere,
to thereby record an image. That is, the above-mentioned liquid
composition is used as a pre-treatment liquid for recording, which,
however, is not limited to the above-mentioned liquid composition.
In this case, an image may be recorded by using the liquid
composition as a post-treatment liquid for recording, and making
the liquid composition adhere onto a recording medium onto which a
predetermined ink has been made to adhere, and an image may be
recorded by using the liquid composition as a recording treatment
liquid and making a predetermined ink and the liquid composition
adhere onto a recording medium at the same time.
EXAMPLES
[0152] Hereinafter, examples of the present invention will be
specifically described, however, the present invention is not
limited to these disclosed examples.
<<Production of Liquid Composition>>
<Production of Polyamine-Epihalohydrin Copolymer, or
Polyamidepolyamine-Epihalohydrin Copolymer>
Production Example A-1
Polyamine-Epihalohydrin Copolymer
[0153] Into a 500 mL-four-necked flask equipped with a stirrer, a
thermometer, a reflux condenser and a nitrogen introduction tube,
95.1 g of water and 131.8 g (0.8 moles) of 58% by mass an aqueous
trimethylamine hydrochloride solution were charged, and 74.0 g (0.8
moles) of epichlorohydrin was added dropwise for 3 hours so as not
to elevate the temperature of the mixture higher than 40.degree.
C., while introducing nitrogen. After the dropwise addition of the
epichlorohydrin was finished, the flask was heated to 80.degree. C.
to allow the mixture to react for 1 hour. Thereafter, the flask was
cooled down to 30.degree. C., and 36.1 g (0.4 moles) of 50% by mass
of aqueous dimethylamine solution and 14.8 g (0.2 moles) of calcium
hydroxide were added in the flask, and then heated to 80.degree. C.
to allow the mixture to react for 1 hour. Thereafter, the reaction
liquid was prepared with hydrochloric acid and water, so as to have
a pH of 4.0 and a solid content concentration of 50% by mass. Thus,
a copolymer represented by Formula (1), i.e., a
polyamine-epihalohydrin copolymer of Production Example A-1 was
produced.
##STR00010##
[0154] in Formula (1), R.sub.1 to R.sub.8 may be identical to or
different from each other, and each denote at least one of an alkyl
group having 1 to 8 carbon atoms, a hydroxyalkyl group, an alkenyl
group, and a benzyl group, X denotes a halogen atom (for example,
F, Cl, Br, I), n denotes an integer of 1 or 2.
Production Example A-2
Polyamine-Epihalohydrin Copolymer
[0155] Into a 500 mL-four-necked flask equipped with a stirrer, a
thermometer, a reflux condenser and a nitrogen introduction tube,
36.8 g of water, 157.6 g (0.8 moles) of 30% by mass aqueous
trimethylamine solution, 36.1 g (0.4 moles) of 50% by mass aqueous
dimethylamine solution, and 7.3 g (0.1 moles) of diethylamine were
charged, and 92.5 g (1.0 mole) of epichlorohydrin was added
dropwise for 4 hours so as not to elevate the temperature of the
mixture higher than 40.degree. C., while introducing nitrogen.
After the dropwise addition of the epichlorohydrin was finished,
the flask was heated to 80.degree. C., and the mixture was allowed
to react at 80.degree. C. for 2 hour. Thereafter, the flask was
cooled down to 30.degree. C. Thereafter, the reaction liquid was
prepared with hydrochloric acid and water, so as to have a pH of
3.9 and a solid content concentration of 50% by mass. Thus, a
copolymer represented by the above Formula (1), i.e., a
polyamine-epihalohydrin copolymer of Production Example A-2 was
produced.
Production Example A-3
Polyamidepolyamine-Epihalohydrin Copolymer
[0156] Into a 3 L-four-necked round flask equipped with a stirrer,
a thermometer, a condenser and a nitrogen introduction tube, 495 g
(4.8 moles) of diethylenetriamine was charged, and 877 g (6.0
moles) of adipic acid was added with stirring. The flask was heated
while generated water was removed from the system, followed by
allowing the mixture to react at 150.degree. C. for 5 hours, and
gradually adding 1,000 g of water, to thereby obtain a
polyamidepolyamine-containing liquid. The
polyamidepolyamine-containing liquid had a solid content of 52.1%
by mass. In the case where the polyamidepolyamine-containing liquid
had a solid content of 50% by mass, it had a viscosity of 380 mPas
at 25.degree. C. Into a flask, 100 g of the
polyamidepolyamine-containing liquid (0.214 moles of an amino
group), 3.8 g (30% by equivalent) of acetic acid, and 4.3 g (15% by
equivalent) of 30% by mass of aqueous sodium hydroxide solution
were charged, and 6.7 g of water was added thereto, so that the
polyamidepolyamine-containing liquid had 50% by mass of solid
content. Next, into the flask, 19.8 g (100% by equivalent) of
epichlorohydrin was added dropwise at 30.degree. C. for 1 hour,
followed by maintaining the resulting mixture at 30.degree. C. for
1 hour, and 0.8 g (2% by equivalent) of sodium metabisulfite was
added thereto, and the flask was maintained at 30.degree. C. for 5
hours from the beginning of the dropwise addition of the
epichlorohydrin. Next, 1.1 g (10% by equivalent) of 98% by mass
sulfuric acid, and 127.0 g of water were added thereto, so that a
solid content thereof had 30% by mass, followed by heating to
75.degree. C. The resulting reaction liquid was maintained at
75.degree. C. until the viscosity of the reaction liquid at
25.degree. C. reached 300 mPas, and then 40.5 g of water was added
thereto so as to obtain a solid content of 26% by mass, followed by
cooling to 25.degree. C. or lower. Thereafter, the pH of the
reaction liquid was adjusted to 3.5 with 30% by mass of sulfuric
acid, and to 3.0 with 88% by mass of formic acid, to thereby
produce a copolymer having a repeating unit represented by Formula
(2) or a copolymer obtained by polymerizing a monomer represented
by Formula (3), a monomer represented by Formula (4) and a monomer
represented by Formula (5), i.e., a
polyamidepolyamine-epihalohydrin copolymer of Production Example
A-3 having a solid content concentration of 25.0% by mass and a
viscosity of 51.6 mPas at a solid content concentration of 15% by
mass.
##STR00011##
[0157] in Formula (2), X denotes a halogen atom (for example, F,
Cl, Br, I), and m denotes an integer of 1 or more. Both-terminal of
the copolymer represented by Formula (2) may be a monomer
constituting a repeating unit, a known initiator, or the like.
##STR00012##
[0158] in Formula (5), X denotes a halogen atom (for example, F,
Cl, Br, and I).
Production Example A-4
Polyamine-Epihalohydrin Copolymer
[0159] Into a 1 L-four-necked flask equipped with a stirrer, a
thermometer, a reflux condenser and a nitrogen introduction tube,
443.85 parts by mass of water, and 41.27 parts by mass of
diethylenetriamine were charged, and 111.04 parts by mass of
epichlorohydrin was added dropwise for 1.5 hours so as not to
elevate the temperature of the mixture higher than 40.degree. C.,
while introducing nitrogen. After the dropwise addition of the
epichlorohydrin was finished, 19.4 parts by mass of
octahydro-4,7-methanoinden-1(2),5(6)-dimethanamine was added to the
mixture, and stirred for 30 minutes, and then 18.51 parts by mass
of epichlorohydrin was added dropwise thereto for half an hour, so
as not to elevate the temperature of the mixture higher than
40.degree. C., followed by heating the resulting mixture to
70.degree. C., and maintaining it at 70.degree. C. for 1.5 hours.
Next, the pH of the mixture was adjusted to 7.5 with 30% by mass of
aqueous sodium hydroxide solution, and the temperature of the
resulting mixture was continuously maintained at 70.degree. C. for
1.5 hours. The pH thereof was adjusted to 3.5 with 30% by mass of
an aqueous sulfuric acid solution, followed by cooling to finish
the reaction. The thus obtained reaction product was a copolymer
containing a monomer represented by the above Formula (3) and a
monomer represented by the above Formula (4) as monomer components,
i.e., a polyamine-epihalohydrin copolymer of Production Example A-4
having a solid content concentration of 30.2% by mass, a viscosity
of 76 mPas at solid content concentration of 10% by mass, and a pH
of 3.9.
Production Example A-5
Polyamine-Epihalohydrin Copolymer
[0160] Into a 1 L-four-necked flask equipped with a stirrer, a
thermometer, a reflux condenser and a nitrogen introduction tube,
657.2 parts by mass of water, 58.4 parts by mass of
triethylenetetramine, and 108 parts by mass of 50% by mass
dimethylamine were charged, and 192.4 parts by mass of
epichlorohydrin was added dropwise for 1.5 hours so as not to
elevate the temperature of the mixture higher than 40.degree. C.,
while introducing nitrogen, followed by heating the resulting
mixture to 70.degree. C., and maintaining it at 70.degree. C. for
1.5 hours. Next, the pH of the mixture was adjusted to 7.5 with 30%
by mass of aqueous sodium hydroxide solution, and the temperature
of the resulting mixture was continuously maintained at 70.degree.
C. for 1.5 hours. The pH thereof was adjusted to 3.5 with 30% by
mass of an aqueous sulfuric acid solution, followed by cooling to
complete the reaction. The thus obtained reaction product was a
copolymer containing a monomer represented by the above Formula (5)
as a monomer component, i.e., a polyamine-epihalohydrin copolymer
of Production Example A-5 having a solid content of 29.9% by mass,
a viscosity of 200 mPas (solid content concentration of 10% by
mass) and a pH of 3.5.
<Production of Liquid Composition>
[0161] Each liquid composition was produced according to the
following procedure. First, materials shown in Tables 1A and 1B
were mixed, and stirred for 1 hour, so as to be uniformly mixed,
thereby obtaining a pretreatment liquid. This pretreatment liquid
was filtered under pressure through a polyvinylidene fluoride
membrane filter having an average pore diameter of 5.0 .mu.m to
remove coarse particles and waste to thereby produce Liquid
Compositions 1 to 13. Physical properties of Liquid Compositions 1
to 13 are shown in Table 2.
[0162] Surface tension: measured at 25.degree. C. using an
automatic surface tension meter (CBVP-Z, produced by Kyowa
Interface Science Co., LTD.)
TABLE-US-00001 TABLE 1A Liquid Composition Component (% by mass) 1
2 3 4 5 6 Organic acid ammonium lactate 6.67 6.67 ammonium
(content: 75%) ammonium acetate 5.15 (content: 97%) Inorganic
calcium nitrate metal salt compound Water-soluble A-1 20.00 20.00
20.00 cationic A-2 20.00 polymer A-3 40.00 A-4 A-5 WS-4020 40.00
20.00 DM-283P Water-soluble 3-methyl-1,3-butanediol 10.00 10.00
20.00 10.00 10.00 10.00 organic glycerin 20.00 20.00 10.00 20.00
20.00 20.00 solvent Penetrant 2-ethyl-1,3-hexanediol 1.00 1.00 1.00
1.00 1.00 1.00 Anti-foaming 2,4,7,9-tetramethyldecane- 0.10 0.10
0.10 0.10 0.10 agent 4,7-diol 2,5,8,11- 0.10 0.10
tetramethyldodecane-5,8- diol KM-72F Fluorine- Compound represented
0.20 0.20 based by Formula (F-1)-e) surfactant Compound represented
0.20 0.30 by Formula (F-2) Compound represented 0.10 by Formula
(F-3-1) Compound represented 0.10 by Formula (F-4-1) Surfactant
SOFTANOL EP7025 Anti-fungal PROXEL GXL 0.05 0.05 0.05 0.05 0.05
0.05 agent Anti-corrosive 1,2,3-benzotriazole 0.05 0.05 0.05 0.05
0.05 0.05 agent Pure water balance balance balance balance balance
balance Total (% by mass) 100 100 100 100 100 100
TABLE-US-00002 TABLE 1B Liquid Composition Component (% by mass) 7
8 9 10 11 12 13 Organic acid ammonium lactate 6.67 6.67 6.67
ammonium (content: 75%) ammonium acetate 10.31 (content: 97%)
Inorganic calcium nitrate 20.41 metal salt compound Water-soluble
A-1 20.00 20.00 cationic A-2 20.00 polymer A-3 A-4 33.33 A-5 33.33
WS-4020 DM-283P 20.00 Water-soluble 3-methyl- 15.00 15.00 15.00
10.00 15.00 10.00 10.00 organic 1,3-butanediol solvent glycerin
20.00 20.00 20.00 20.00 15.00 20.00 20.00 Penetrant 2-ethyl-1,3-
1.00 1.00 1.00 1.00 1.00 1.00 hexanediol Anti-foaming 2,4,7,9- 0.10
0.10 0.10 0.10 0.10 agent tetramethyldecane- 4,7-diol 2,5,8,11-
tetramethyldodecane- 5,8-diol KM-72F 0.10 Fluorine- Compound 0.20
0.20 0.20 0.20 0.20 based represented by surfactant Formula
(F-1)-e) Compound represented by Formula (F-2) Compound represented
by Formula (F-3-1) Compound represented by Formula (F-4-1)
Surfactant SOFTANOL 0.50 0.50 EP7025 Anti-fungal PROXEL GXL 0.05
0.05 0.05 0.05 0.05 0.05 0.05 agent Anti-corrosive
1,2,3-benzotriazole 0.05 0.05 0.05 0.05 0.05 0.05 0.05 agent Pure
water balance balance balance balance balance balance balance Total
(% by mass) 100 100 100 100 100 100 100
[0163] Abbreviations in Tables 1A and 1B denote the following
meanings: [0164] ammonium lactate: produced by Kanto Chemical Co.,
Inc., purity: 73% to 77% [0165] ammonium acetate: produced by Kanto
Chemical Co., Inc., purity: 97% or more [0166] WS-4020:
polyamide-epichlorohydrin copolymer (produced by SEIKO PMC
CORPORATION, effective component: 25% by mass) [0167] SOFTANOL
EP-7025: polyoxyalkylene alkylether (produced by Nippon Shokubai
Co., Ltd., component: 100% by mass) [0168] PROXEL GXL: anti-fungal
agent mainly containing 1,2-benzisothiazolin-3-one (produced by
Avicia Co., component: 20% by mass, containing dipropylene glycol)
[0169] SHAROLL DM-283P: quaternary ammonium salt type cationic
polymer compound (produced by DAI-ICHI KOGYO SEIYAKU CO., LTD., an
aqueous solution containing 50% by mass of effective component,
molecular weight: about 28,000) represented by the following
Formula (8).
##STR00013##
[0170] in Formula (8), X denotes a halogen atom, and n denotes an
integer or 1 or more.
TABLE-US-00003 TABLE 2 Liquid Surface tension composition pH (mN/m)
1 6.44 20.6 2 5.78 20.8 3 5.19 25.7 4 6.43 20.7 5 6.45 26.2 6 6.96
20.9 7 6.24 21.4 8 5.98 20.5 9 6.28 20.7 10 6.17 30.9 11 6.82 31.3
12 4.89 20.9 13 6.47 20.9
<<Production of Ink>>
<Production of Resin Coating Pigment Dispersion>
(Production of Resin Coating Polymer)
[0171] Into a reaction vessel, 20 parts by mass of methyl ethyl
ketone, 0.03 parts by mass of a polymerization chain transfer agent
(2-mercaptoethanol), and 10% by mass of each monomer shown in Table
3 (represented by parts by mass) were charged, mixed, and then the
reaction vessel was sufficiently purged with nitrogen gas, to
thereby obtain a mixture solution. Meanwhile, in a dropping funnel,
remained 90% by mass of each of the monomers shown in Table 3
(represented by parts by mass) was charged, and subsequently 0.27
parts by mass of a polymerization chain transfer agent
(2-mercaptoethanol), 60 parts by mass of methyl ethyl ketone and
1.2 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) were
added, mixed, and then the dropping funnel was sufficiently purged
with nitrogen gas, to thereby obtain a mixture solution.
[0172] The temperature of the mixture solution in the reaction
vessel was increased to 75.degree. C. while being stirred under a
nitrogen atmosphere, and the mixture solution in the dropping
funnel was gradually added dropwise to the reaction vessel for 3
hours. After completion of the dropping, the temperature of the
resulting mixture solution was maintained at 75.degree. C. for 2
hours. Subsequently, a solution, in which 0.3 parts by mass of
2,2'-azobis(2,4-dimethylvaleronitrile) were dissolved in 5 parts by
mass of methyl ethyl ketone, was added to the mixture solution, and
the system was further aged at 75.degree. C. for 2 hours and at
85.degree. C. for 2 hours to thereby obtain each solution of Resin
Coating Polymers 1 to 4.
[0173] Part of the resulting resin coating polymer solution was
dried at 105.degree. C. for 2 hours under reduced pressure and
isolated by removing the solvent therefrom. A weight average
molecular weight of the resulting resin coating polymer was
measured by gel permeation chromatography, using polystyrene
serving as a standard material, 60 mmol/L of phosphoric acid and 50
mmol/L of lithium bromide-containing dimethylformamide each serving
as a solvent.
TABLE-US-00004 TABLE 3 Resin coating polymer Monomer (% by mass) 1
2 3 4 (A) ethoxy polyethylene glycol 10 monomethacrylate octoxy
polyethylene glycol 10 monomethacrylate octoxy polyethylene glycol-
10 polypropylene glycol monomethacrylate lauroxy polyethylene
glycol 10 monomethacrylate (B) methacrylic acid 12 12 14 14 (C)
2-ethylhexyl methacrylate 22 22 20 20 styrene monomer 46 46 46 46
styrene macromer 10 10 10 10 Weight average molecular weight 32,000
41,000 40,000 30,000 Neutralization degree (%) 90 90 90 90
[0174] Note that details of individual compounds shown in Table 3
are as follows: [0175] octoxypolyethylene glycol-polyproplylene
glycol monomethacrylate: a monomer to which an oxyethylene group
and an oxypropylene group are randomly added (average number of
moles added of polyethylene glycol: 4, average number of moles
added of polypropylene glycol: 2) [0176] methacrylic acid: produced
by Mitsubishi Gas Chemical Co, Inc., product name: GE-110 (MAA)
[0177] 2-ethylhexyl methacrylate: produced by Mitsubishi Rayon Co.,
Ltd., product name: ACRYESTER EH [0178] styrene monomer: produced
by Nippon Steel Chemical Co., Ltd., product name: STYRENEMONOMER
[0179] styrene macromer: produced by TOAGOSEI Co., Ltd., product
name: AS-6S (styrene macromer), number average molecular weight:
6,000
(Production of Resin Coating Pigment Dispersion)
[0180] To 77 parts by mass of a solution, in which the
concentration of each of the resin coating polymers 1 to 4 obtained
in the above-mentioned production example was adjusted to 50% by
mass with methyl ethyl ketone, 90 parts by mass of methyl ethyl
ketone and a predetermined amount of a neutralizing agent (5N
aqueous sodium hydroxide solution) were added to neutralize the
methacrylic acid (neutralization degree: 90%). Subsequently, 370
parts by mass of ion exchanged water were added thereto and
further, 90 parts by mass of a pigment shown in Table 4 were added
as a colorant thereto, and the components were mixed using a
homogenizer, followed by 20 passes of dispersion treatment by a
dispersing machine (MICROFLUIDIZER M-140K, 150 MPa). Note that the
resin coating pigment dispersions is using Carbon Black NIPEX 150
were subjected to 5 passes of dispersion treatment with the
dispersing machine.
[0181] To the resulting water dispersion, 100 parts by mass of ion
exchanged water were added, stirred, and the methyl ethyl ketone
was removed therefrom at 60.degree. C. under reduced pressure.
Further, part of water was removed from the water dispersion, and
then filtered through a needle-less syringe (capacity: 25 mL)
(produced by TERUMO Corporation) to which a 5 .mu.m-filter (acetyl
cellulose film, outer diameter: 2.5 cm, produced by FUJIFILM
Corporation) was attached to remove coarse particles therefrom,
thereby obtaining aqueous dispersions of Production Examples B-1 to
B-4 (solid content: 25% by mass).
TABLE-US-00005 TABLE 4 Resin Production coating Example polymer
Pigment B-1 1 Carbon Black NIPEX150 (produced by Degussa HULS AG)
B-2 2 C.I. Pigment Yellow 74 (produced by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) B-3 3 C.I. Pigment Red 122 (produced by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) B-4 4 C.I.
Pigment Blue 15:3 (produced by Dainichiseika Color & Chemicals
Mfg. Co., Ltd.)
<Production of Pigment-Surfactant Dispersion>
Production Example C-1
Black Pigment-Surfactant Dispersion
TABLE-US-00006 [0182] Carbon Black (NIPEX150, produced by 15.0
parts by mass Degussa HULS AG) polyoxyethylene styrene phenylether
sulfonate 6.0 parts by mass ammonium (anionic surfactant, produced
by DAI-ICHI KOGYO SEIYAKU CO., LTD., HITENOL NF-17) ion exchanged
water 79.0 parts by mass
[0183] First, the surfactant listed above was dissolved in ion
exchanged water, the carbon black was mixed therewith, and the
sufficiently wetted. Then, the system was subjected to 5 passes of
dispersion treatment with MICROFLUIDIZER M-140K, 150 MPa
(manufactured by Mizuho Kogyo K.K.) to obtain a primary pigment
dispersion. Next, to the primary pigment dispersion, 2.13 parts by
mass of a water-soluble polyurethane resin (TAKELAC W-5661,
produced by Mitsui Chemicals, Inc., effective component: 35.2% by
mass, acid value: 40 mgKOH/g, molecular weight: 18,000) were added
as a water-soluble polymer compound aqueous solution, and
sufficiently stirred to thereby obtain a black pigment-surfactant
dispersion of Production Example C-1. An average particle diameter
(D.sub.50) of the pigment dispersion in the resulting black
pigment-surfactant dispersion was 132 nm as measured with a
particle size distribution measurement device (manufactured by
NIKKISO Co., Ltd., NANOTRACK UPA-EX150).
Production Example C-2
Yellow Pigment-Surfactant Dispersion
TABLE-US-00007 [0184] monoazo yellow pigment (C.I. Pigment Yellow
20.0 parts by mass 74, produced by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) polyoxyethylene-.beta.-naphthylether
(nonionic 7.0 parts by mass surfactant, produced by TAKEMOTO OIL
& FAT Co., RT-100, HLB value = 18.5) ion exchanged water 73.0
parts by mass
[0185] First, the surfactant listed above was dissolved in ion
exchanged water, the pigment listed above was mixed therewith, and
then sufficiently wetted. Then, the system was dispersed at 2,000
rpm for 2 hours by a wet-process dispersing machine (DYNOMILL KDL A
Model, manufactured by WAB) which was filled with zirconia beads
having a diameter of 0.5 mm, to obtain a primary pigment
dispersion. Next, to the primary pigment dispersion, 2.84 parts by
mass of a water-soluble polyurethane resin (TAKELAC W-5661,
produced by Mitsui Chemicals, Inc., effective component: 35.2% by
mass, acid value: 40 mgKOH/g, molecular weight: 18,000) were added
as a water-soluble polymer compound aqueous solution, and
sufficiently stirred to thereby obtain a yellow pigment-surfactant
dispersion of Production Example C-2. An average particle diameter
(D.sub.50) of the pigment dispersion in the resulting yellow
pigment-surfactant dispersion was 76 nm as measured with a particle
size distribution measurement device (manufactured by NIKKISO Co.,
Ltd., NANOTRACK UPA-EX150).
Production Example C-3
Magenta Pigment-Surfactant Dispersion
TABLE-US-00008 [0186] quinacridone pigment (C.I. Pigment Red 122,
20.0 parts by mass produced by Dainichiseika Color & Chemicals
Mfg. Co., Ltd.) polyoxyethylene-.beta.-naphthylether (nonionic 7.0
parts by mass surfactant, produced by TAKEMOTO OIL & FAT Co.,
RT-100, HLB value = 18.5) ion exchanged water 73.0 parts by
mass
[0187] A magenta pigment-surfactant dispersion of Production
Example C-3 was produced in the same manner as in a yellow
pigment-surfactant dispersion of Production Example C-2, except
that the pigment was changed to quinacridone pigment. An average
particle diameter (D.sub.50) of the pigment dispersion in the
resulting magenta pigment-surfactant dispersion was 86 nm as
measured with a particle size distribution measurement device
(manufactured by NIKKISO Co., Ltd., NANOTRACK UPA-EX150).
Production Example C-4
Cyan Pigment-Surfactant Dispersion
TABLE-US-00009 [0188] phthalocyanine pigment (C.I. Pigment Blue
20.0 parts by mass 15:3, produced by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) polyoxyethylene-.beta.-naphthylether
(nonionic 7.0 parts by mass surfactant, produced by TAKEMOTO OIL
& FAT Co., RT-100, HLB value = 18.5) ion exchanged water 73.0
parts by mass
[0189] A cyan pigment-surfactant dispersion of Production Example
C-4 was produced in the same manner as in a yellow
pigment-surfactant dispersion of Production Example C-2, except
that the pigment was changed to phthalocyanine pigment. An average
particle diameter (D.sub.50) of the pigment dispersion in the
resulting cyan pigment-surfactant dispersion was 106 nm as measured
with a particle size distribution measurement device (manufactured
by NIKKISO Co., Ltd., NANOTRACK UPA-EX150).
<Preparation of Ink>
[0190] Each inkjet ink was produced according to the following
procedure. First, a water-soluble organic solvent, a penetrant, a
surfactant, an anti-fungal agent and water shown in Tables 5-1 and
5-2 were mixed and stirred for 1 hour so as to be uniformly mixed.
In addition, depending on the mixture liquid, a water-dispersible
resin was added, and stirred for 1 hour. Further, the pigment
dispersion, an anti-foaming agent and a pH adjustor were added to
the mixture liquid and stirred for 1 hour. This dispersion liquid
was filtered under pressure through a polyvinylidene
fluoride-membrane filter having an average pore diameter of 5.0
.mu.m to remove coarse particles and waste therefrom, thereby
producing Inks (K1 to K4, Y1 to Y4, M1 to M4, and C1 to C4) shown
in Tables 5-1 and 5-2.
TABLE-US-00010 TABLE 5-1 Ink Component (% by mass) K1 Y1 M1 C1 K2
Y2 M2 C2 Pigment Production Ex. B-1 45.71 dispersion Production Ex.
B-2 28.57 Production Ex. B-3 45.71 Production Ex. B-4 28.57
Production Ex. C-1 53.33 Production Ex. C-2 25.00 Production Ex.
C-3 40.00 Production Ex. C-4 25.00 Water-dispersible
acryl-siliconeresin emulsion 2.50 3.75 2.50 3.75 resin
Water-soluble 1,3-butanediol 13.00 18.00 19.00 26.00 22.0 25.00
organic solvent 3-methyl-1,3-butanediol 16.00 15.00 glycerin 16.00
26.00 18.00 19.00 15.00 13.00 11.00 12.50 Penetrant
2-ethyl-1,3-hexanediol 2.00 2.00 2.00 2.00
2,2,4-trimethyl-1,3-pentanediol 2.00 2.00 2.00 2.00 Anti-foaming
2,4,7,9-tetramethyldecane-4,7-diol 0.40 0.25 0.25 0.25 0.25 agent
2,5,8,11-tetramethyldodecane-5,8-diol 0.40 0.40 0.40 KM-72F
Fluorine-based Compound represented by (F-1)-e) 0.10 0.10 0.10 0.10
surfactant Compound represented by (F-2) 0.05 0.05 0.05 0.05
Compound represented by (F-3-1) Compound represented by (F-4-1)
Anti-fungal agent PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05
0.05 pH adjustor 2-amino-2-ethyl-1,3-propanediol 0.30 0.40 0.40
0.40 0.60 0.30 0.30 0.30 Pure water balance balance balance balance
balance balance balance balance Total (% by mass) 100 100 100 100
100 100 100 100
TABLE-US-00011 TABLE 5-2 Ink Component (% by mass) K3 Y3 M3 C3 K4
Y4 M4 C4 Pigment Production Ex. B-1 22.86 dispersion Production Ex.
B-2 5.71 Production Ex. B-3 9.14 Production Ex. B-4 5.71 Production
Ex. C-1 26.67 Production Ex. C-2 20.00 Production Ex. C-3 32.00
Production Ex. C-4 20.00 Black self-dispersible pigment 53.33
dispersion (CAB-O-JET300) Yellow self-dispersible pigment 45.45
dispersion (CAB-O-JET270) Magenta self-dispersible pigment 54.55
dispersion (CAB-O-JET260) Cyan self-dispersible pigment 45.45
dispersion (CAB-O-JET250) Water-soluble 1,3-butanediol 27.50 26.00
27.60 25.00 22.00 24.00 organic 3-methyl-1,3-butanediol 16.50 15.00
solvent glycerin 16.50 13.75 13.00 13.80 15.50 12.50 11.00 12.00
Penetrant 2-ethyl-1,3-hexanediol 2.00 2.00 2.00 2.00 2.00 2.00 2.00
2.00 2,2,4-trimethyl-1,3-pentanediol Anti-foaming
2,4,7,9-tetramethyldecane-4,7-diol 0.25 0.25 0.25 0.25 agent
2,5,8,11-tetramethyldodecane-5,8-diol KM-72F 0.10 0.10 0.10 0.10
Fluorine-based Compound represented by (F-1)-e) 0.05 0.05 0.05 0.05
surfactant Compound represented by (F-2) Compound represented by
(F-3-1) 0.05 Compound represented by (F-4-1) 0.05 0.05 0.05
Anti-fungal PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 pH
adjustor 2-amino-2-ethyl-1,3-propanediol 0.60 0.30 0.30 0.30 1.20
0.30 0.30 0.30 Pure water balance balance balance balance balance
balance balance balance Total (% by mass) 100 100 100 100 100 100
100 100
[0191] Abbreviations in Tables 5-1 and 5-2 denote the following
meanings: [0192] CAB-O-JET 260: produced by Cabot Corporation,
pigment solid content: 11% by mass, self-dispersible magenta
pigment [0193] CAB-O-JET 250: produced by Cabot Corporation,
pigment solid content: 11% by mass, self-dispersible cyan pigment
[0194] CAB-O-JET 270: produced by Cabot Corporation, pigment solid
content: 11% by mass, self-dispersible yellow pigment [0195]
CAB-O-JET 300: produced by Cabot Corporation, pigment solid
content: 15% by mass, self-dispersible black pigment [0196]
acryl-silicone resin emulsion: produced by Showa High Polymer Co.,
Ltd., POLYZOLE ROY6312, solid content: 40% by mass, average
particle diameter: 171 nm, minimum film-forming temperature (MFT):
20.degree. C. [0197] PROXEL GXL: anti-fungal agent mainly
containing 1,2-benzisothiazolin-3-one (produced by Avicia Co.,
component: 20% by mass, containing dipropylene glycol) [0198]
KM-72F: self-emulsified type silicone anti-foaming agent (produced
by Shin-Etsu silicone Corp., component: 100% by mass)
[0199] Next, each of the inks produced as described above was
evaluated according to the following evaluation methods. The
evaluation results are shown in Table 6. [0200] Average particle
diameter (D.sub.50): measured at 25.degree. C. with a particle size
distribution measurement device (NANOTRACK UPA-EX150, manufactured
by NIKKISO Co., Ltd.) [0201] Viscosity: measured at 25.degree. C.
with a viscometer (RE-550L, manufactured by TOKI SANGYO Co., Ltd.)
[0202] Surface tension: measured at 25.degree. C. with an automatic
surface tension meter (CBVP-Z, manufactured by Kyowa Interface
Science Co., LTD.)
TABLE-US-00012 [0202] TABLE 6 Physical Properties of Ink Average
particle Viscosity Surface tension diameter D.sub.50 (nm) (mPa s)
(mN/m) K1 79.5 8.10 21.5 Y1 95.6 7.98 21.0 M1 95.9 8.03 21.3 C1
81.3 8.00 20.9 K2 133.3 8.08 22.4 Y2 82.4 8.00 21.7 M2 92.6 8.09
21.6 C2 108.6 8.14 21.6 K3 110.4 6.25 24.9 Y3 92.8 6.12 25.1 M3
135.2 6.41 25.0 C3 130.1 6.26 25.2 K4 124.1 7.92 24.5 Y4 84.1 7.85
23.5 M4 94.5 7.88 24.7 C4 98.8 7.89 24.7
<<Step of Making Liquid Composition Adhere onto Recording
Medium>>
[0203] In Examples and Comparative Examples other than Comparative
Examples 1 to 4, each of Liquid Compositions 1 to 13 shown in Table
7 was applied, in an adhesion amount of 0.8 g/m.sup.2, to the
following recording medium by a roll coating method, using the
recording apparatus illustrated in FIG. 2 or FIG. 3, and then
naturally dried.
[0204] Recording medium: recycle PPC produced by DAIO PAPER
CORPORATION (recycled paper), basis weight: 66.5 g/m.sup.2,
compounding ratio of recycled fiber 70% or higher, sizing degree:
17 sec., and air permeability: 35 sec.
<<Step of Making Ink Adhere onto Recording Medium>>
[0205] In the step of making an ink adhere onto a recording medium,
concerning each Examples and Comparative Examples, using an inkjet
recording apparatus (IPSIO GX5000, manufactured by Ricoh Company,
Ltd.) to which an ink set described in Table 7 had been mounted, an
image was recorded by applying an ink onto the recording medium
shown in Table 7 which had been produced by the step of making a
liquid composition onto the recording medium, and thereby recording
an image. Concerning Comparative Examples 1 to 4 in Table 7, each
ink was applied to a recording medium (RECYCLE PPC) on which
surface no liquid composition was applied, thereby recording an
image. Since images recorded differ for every evaluation item, and
thus the details of the images will be described in "Evaluation of
Recorded Matter" below. Note that at the time of applying an ink to
the recording medium, the driving voltage of a piezoelectric
element was varied so that the discharge amounts of the individual
inks were equal to each other, under the environment of 23.degree.
C..+-.0.5.degree. C. and 50% RH.+-.5% RH. In addition, the printing
mode when each ink was applied was set to "Plain Paper/Clear Mode,
Color Matching: OFF".
TABLE-US-00013 TABLE 7 Liquid composition Ink set Ex. 1 1 1 Ex. 2 2
2 Ex. 3 3 3 Ex. 4 4 1 Ex. 5 5 4 Ex. 6 6 1 Ex. 7 7 4 Ex. 8 8 1 Ex. 9
9 4 Ex. 10 10 1 Ex. 11 6 1 Ex. 12 6 2 Ex. 13 6 3 Ex. 14 13 1 Comp.
Ex. 1 1 Comp. Ex. 2 2 Comp. Ex. 3 3 Comp. Ex. 4 4 Comp. Ex. 5 11 4
Comp. Ex. 6 12 1
[0206] Note that, each of the ink sets shown in Table 7 is composed
of the inks described below.
[0207] Ink Set 1: Ink M1, Ink C1, Ink Y1, Ink K1
[0208] Ink Set 2: Ink M2, Ink C2, Ink Y2, Ink K2
[0209] Ink Set 3: Ink M3, Ink C3, Ink Y3, Ink K3
[0210] Ink Set 4: Ink M4, Ink C4, Ink Y4, Ink K4
<<Evaluation of Recorded Matter>>
[0211] Recording matters obtained using Examples and Comparative
Examples were evaluated for the following items.
<Image Density>
[0212] Concerning a recorded matter which was recorded by means of
MICROSOFT Word 2000, in which a character ".box-solid." was
recorded (font size: 64 point), the density of the ".box-solid."
portion on a recorded surface was measured with an X-Rite 938
(produced by X-Rite). The image density was evaluated in such a
manner that one color which was evaluated worst among four colors
was selected, and then evaluated based on the following
criteria.
[Evaluation Criteria]
[0213] A: Black: 1.45 or higher,
[0214] Yellow: 0.90 or higher,
[0215] Magenta: 1.15 or higher, or
[0216] Cyan: 1.20 or higher. [0217] B: Black: 1.35 or higher but
lower than 1.45,
[0218] Yellow: 0.85 or higher but lower than 0.90,
[0219] Magenta: 1.05 or higher but lower than 1.15, or
[0220] Cyan: 1.10 or higher but lower than 1.20. [0221] C: Black:
lower than 1.35,
[0222] Yellow: lower than 0.85,
[0223] Magenta: lower than 1.05, or
[0224] Cyan: lower than 1.10.
<Strikethrough>
[0225] A recorded matter which was recorded by means of MICROSOFT
Word 2000, in which a character ".box-solid." was recorded (font
size: 64 point), was measured for colorimetry at its rear surface
to the recorded surface where ".box-solid." was recorded, by an
X-Rite 938. A density obtained by subtracting the density of the
background of the recording medium was regarded as "strikethrough
density". The measured strikethrough density was judged in such a
manner that one color which was evaluated worst among four colors
was selected, and then evaluated based on the following
criteria.
[Evaluation Criteria]
[0226] A: Black: lower than 0.09,
[0227] Yellow: lower than 0.08,
[0228] Magenta: lower than 0.09, or
[0229] Cyan: lower than 0.09. [0230] B: Black: 0.09 or higher but
lower than 0.10,
[0231] Yellow: 0.08 or higher but lower than 0.09,
[0232] Magenta 0.09 or higher but lower than 0.10, or
[0233] Cyan: 0.09 or higher but lower than 0.10. [0234] C: Black:
0.10 or higher,
[0235] Yellow: 0.09 or higher,
[0236] Magenta: 0.10 or higher, or
[0237] Cyan: 0.10 or higher.
<Color Bleeding>
[0238] Concerning a recorded matter on which surface 0.5-mm line
images for each color of magenta, cyan and black were recorded on a
yellow solid image, occurrence of bleeding at color boundary where
different color inks were recorded was visually observed. Similarly
to the above, a recorded matter on which surface 0.5-mm line images
for each color of magenta, yellow and black were recorded on a cyan
solid image, and a recorded matter on which surface 0.5-mm line
images for each color of cyan, yellow and black were recorded on a
magenta solid image were also visually observed for presence or
absence of bleeding at color boundary.
[Evaluation Criteria]
[0239] A: No problem at all
[0240] B: Slightly occurred but no problem
[0241] C: Occurred, problematic
<Feathering>
[0242] Concerning a recorded matter which was recorded by means of
MICROSOFT Word 2000, in which a black character shown below was
recorded (font size: 6 point), occurrence of feathering in the
following character portion was visually observed.
[0243] [Evaluation Criteria]
[0244] A: No problem at all
[0245] B: Slightly occurred but no problem
[0246] C: Occurred in small percentage, problematic
[0247] D: Occurred, problematic
<White-Out>
[0248] Concerning a recorded matter which was recorded by means of
MICROSOFT Word 2000, in which a character ".box-solid." was
recorded in each color of yellow, magenta, cyan, and black (font
size: 64 point), the ".box-solid." portion was visually observed,
and presence or absence of white-out (void portions in the
character ".box-solid.") was evaluated.
[Evaluation Criteria]
[0249] A: No problem at all
[0250] B: Slightly observed, but no problem
[0251] C: Observed, but within an allowable range
[0252] D: Problematic
<Abrasion Resistance>
[0253] A recorded matter which was recorded by means of MICROSOFT
Word 2000, in which a monochrome black solid image (3 cm.times.3
cm) was recorded, was dried at 23.degree. C..+-.1.degree. C. and
50% RH.+-.10% RH for 24 hours. Subsequently, JIS L 0803 Cotton No.
3 that had been attached to a CM-1 model clockmeter with a
double-sided tape was moved to-and-fro on the recorded matter 5
times so that it was applied to the monochrome black solid image in
the recorded matter, and then the density of the cotton cloth to
which the ink had been attached was measured with an X-Rite 938.
The density of the background color of the cotton cloth was
subtracted from the measured density value, and the result was
regarded as a density of smeared portions. The density of the
smeared portions was judged based on the following evaluation
criteria.
[Evaluation Criteria]
[0254] A: lower than 0.15
[0255] B: 0.15 or higher but lower than 0.25
[0256] C: 0.25 or higher
<Drying Properties>
[0257] A recorded matter which was recorded by means of MICROSOFT
Word 2000, in which a monochrome black solid image (3 cm.times.3
cm) was produced. Subsequently, immediately after the recording of
the image (10 seconds later), JIS L 0803 Cotton No. 3 that had been
attached to a CM-1 model clockmeter with a double-sided tape was
moved to-and-fro on the recorded matter 5 times so that it was
applied to the monochrome black solid image in the recorded matter,
and then the density of the cotton cloth to which the ink had been
attached was measured by an X-Rite 938. The density of the
background color of the cotton cloth was subtracted from the
measured density value, and the result was regarded as a density of
smeared portions. The density of the smeared portions was judged
based on the following evaluation criteria. Note that the
evaluation was performed under the environment of 23.degree.
C..+-.1.degree. C. and 50% RH.+-.10% RH.
[Evaluation Criteria]
[0258] A: lower than 0.2
[0259] B: 0.2 or higher but lower than 0.3
[0260] C: 0.3 or higher
[0261] The evaluation results are shown in Table 8. The inks were
evaluated for each color based on the evaluation criteria described
above. Note that as for the results of image quality of recorded
matters, the most common evaluation judgment was described as the
result. When the number of evaluation judgments was equal, the
better judgment was described as the result.
<Evaluation of Liquid Composition Coatability>
[0262] A recording medium was coated with the liquid composition
using a roll coater. Foaming of the liquid composition in a coating
device and coatability of the liquid composition to the recording
medium were visually observed, and evaluated based on the following
evaluation criteria.
[Evaluation Criteria]
[0263] A: Foaming hardly occurred, and coatability of the liquid
composition to the recording medium was good.
[0264] B: Foaming occurred, but antifoaming ability was good, thus,
the coatability of the liquid composition to the recording medium
was good.
[0265] C: Foaming severely occurred, and the antifoaming ability
was poor, thus, coating failure of the liquid composition to the
recording medium occurred.
TABLE-US-00014 TABLE 8 Coatability Image Strike- Color White-
Abrasion Drying of liquid density through Feathering bleeding out
resistance properties composition Ex. 1 B B B A A A A A Ex. 2 B B B
A B A A A Ex. 3 B B B A B B B A Ex. 4 A A A A A A A A Ex. 5 A A A A
A A A A Ex. 6 B A B A A A A A Ex. 7 A A A A A A A A Ex. 8 A A A A A
A B A Ex. 9 B A B A A A A A Ex. 10 B B B A B A B B Ex. 11 B A B A A
A A A Ex. 12 B A B A A A A A Ex. 13 B A B A B B A A Ex. 14 A A A A
A A A C Comp. Ex. 1 C C B B B B B -- Comp. Ex. 2 C C C C C A A --
Comp. Ex. 3 C C C C C A A -- Comp. Ex. 4 C C C C C A A -- Comp. Ex.
5 A A A A B C C C Comp. Ex. 6 C C B B B B B A
REFERENCE SIGNS LIST
[0266] 1 liquid composition [0267] 2 film thickness control roller
[0268] 3 pump-up roller [0269] 4 applying roller [0270] 5 counter
roller [0271] 6 recording medium [0272] 7 paper feeding roller
[0273] 8 paper feeding tray [0274] 10 paper feed roller [0275] 11
recording medium feed roller [0276] 12 recording medium feed roller
[0277] 13 recording medium feed roller [0278] 14 recording medium
feed roller [0279] 15 recording medium feed roller [0280] 16
recording medium feed roller [0281] 17 recording medium [0282] 18
paper feeding roller [0283] 20 recording head [0284] 21 ink
cartridge [0285] 22 carriage shaft [0286] 23 carriage [0287] 31
recording medium guide [0288] 32 recording medium feed roller
[0289] 33 recording medium feed roller [0290] 34 recording medium
send-back roller [0291] 35 paper feed guide [0292] 101 recording
medium [0293] 102 liquid composition-attached portion [0294] 103
negatively charged and colorant-containing particles [0295] 104
vehicle
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